Journal of Catalysis最新文献

{"title":"How far is far? Weak noncovalent interactions govern enantioselective cyclopropanation catalyzed by ruthenium phthalocyanine with remote (R)-BINOL substituents","authors":"Alexander A. Dmitrienko ,&nbsp;Andrey P. Kroitor ,&nbsp;Liudmila I. Demina ,&nbsp;Gayane A. Kirakosyan ,&nbsp;Yulia G. Gorbunova ,&nbsp;Aslan Yu. Tsivadze ,&nbsp;Alexander G. Martynov ,&nbsp;Alexander B. Sorokin","doi":"10.1016/j.jcat.2025.116443","DOIUrl":"10.1016/j.jcat.2025.116443","url":null,"abstract":"<div><div>A chiral <em>bis</em>-(<em>R</em>-binaphthoxy)-bridged ruthenium phthalocyanine complex was synthesized and examined in the cyclopropanation of styrene derivatives with diazo esters. Despite the asymmetry-inducing chiral substituents in the phthalocyanine ligand being positioned at a considerable distance from the catalytic center, the complex exhibits significant stereoselectivity, depending on the nature of the substrates. Specifically, switching from ethyl diazoacetate (EDA) to the bulkier <em>tert</em>-butyl diazoacetate (<em>^t</em>BuDA) dramatically improved the <em>trans</em>/<em>cis</em> ratio from 6:1 to 49:1 and the enantiomeric excess from 27 % to 71 % for the (<em>S</em>,<em>S</em>)-cyclopropane derivative of styrene. Furthermore, extremely high <em>trans</em>/<em>cis</em> ratios (up to 499:1) and promising enantiomeric excesses (up to 83 %) were achieved using various substituted styrenes. Most reactions were carried out with an exceptionally low catalyst loading of 0.02 mol%. A detailed DFT computational study of the reaction between styrene and <em>^t</em>BuDA accurately reproduced the experimental cyclopropanation enantioselectivity, explaining the preferential formation of the (<em>S</em>,<em>S</em>)-cyclopropane derivative. Non-covalent interaction analysis within quantum theory of atoms in molecules (QTAIM) and energy decomposition analysis (ETS-NOCV) both revealed that weak interactions played a crucial role in stabilizing the enantio-determining transition states. This work firmly demonstrates that a catalytic system with a properly designed rigid chiral cavity combined with an appropriate carbene can achieve promising asymmetric induction, even when the chiral substituents are remote from the catalytic center.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"452 ","pages":"Article 116443"},"PeriodicalIF":6.5,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145077919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel proline p-toluenesulfonate ionic liquid as a recyclable catalyst for lauric acid esterification: process optimisation, kinetic and thermodynamic studies","authors":"Hao Chen ,&nbsp;Ying Zeng ,&nbsp;Guangjin Hu ,&nbsp;Zelin Liu ,&nbsp;Lifei Zou ,&nbsp;Benyong Han","doi":"10.1016/j.jcat.2025.116440","DOIUrl":"10.1016/j.jcat.2025.116440","url":null,"abstract":"<div><div>In this study, eight amino acid-based p-toluenesulfonic acid ionic liquids ([AAH][C₇H₇O₃S]-ILs) were successfully prepared by the neutralisation reaction of natural amino acids with p-toluenesulfonic acid (p-TSA). The catalytic performance of the newly synthesized [AAH][C₇H₇O₃S]-ILs was systematically investigated for biodiesel preparation using lauric acid and ethanol as model reactants. Experimental results demonstrated that proline p-toluenesulfonic acid ionic liquid ([ProH][C₇H₇O₃S]) exhibited optimal catalytic performance for esterification of lauric acid and ethanol with a lower <em>H</em>₀ (1.6601). Response surface methodology (RSM) optimized the process conditions to achieve 96.1 % lauric acid conversion under the following conditions: 14.4 wt.% catalyst loading, 16.3:1 ethanol/lauric acid molar ratio, 2.46 h reaction time, and 89 °C temperature. According to the ¹H NMR method, the yield of biodiesel (ethyl laurate) was determined to be 96.0 %. The kinetic investigation revealed that the reaction followed first-order kinetic, exhibiting relatively low activation energy (7.04 kJ•mol⁻¹) and a frequency factor reaching 0.208 min⁻¹. Calculated thermodynamic parameters showed ΔH = 3.94 kJ•mol⁻¹, ΔS = -0.268kJ•mol⁻¹•K⁻¹, ΔG = 103.9kJ•mol⁻¹. After undergoing ten reaction cycles, the catalyst maintained 93.9 % of its initial catalytic activity, confirming its excellent structural stability. It was noteworthy that [ProH][C₇H₇O₃S] exhibited homogeneous catalytic properties during the reaction, and the system can achieve spontaneous liquid–liquid partitioning after the reaction, which significantly simplifies the product separation process. The catalyst had the advantages of high catalytic efficiency, green renewability and easy operation, which provided a new catalytic system with the potential of industrialisation for biodiesel production.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"452 ","pages":"Article 116440"},"PeriodicalIF":6.5,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145077909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lewis acid-base interactions of oxide support for enhanced C–C coupling and deoxygenation reactions","authors":"Kishore Rajendran ,&nbsp;Dipika Rajendra Kanchan ,&nbsp;Ajaikumar Samikannu ,&nbsp;Petter Tingelstad ,&nbsp;Zhihui Li ,&nbsp;Albert Miró i Rovira ,&nbsp;Arghya Banerjee ,&nbsp;Jyri-Pekka Mikkola ,&nbsp;Kumar Ranjan Rout ,&nbsp;De Chen","doi":"10.1016/j.jcat.2025.116435","DOIUrl":"10.1016/j.jcat.2025.116435","url":null,"abstract":"<div><div>The transition to sustainable energy systems requires efficient catalysts capable of upgrading biomass into liquid fuels and platform chemicals to meet future energy demands. Metal oxides, as supports in bifunctional catalysts, are pivotal due to their ability to provide active sites, create oxygen vacancy defects, and facilitate electron transfer. While these properties are well-studied in the presence of metal nanoparticles, the intrinsic activity and surface properties of stand-alone oxide supports remain underexplored.</div><div>This study investigates the role of bare metal oxides (TiO₂, ZrO₂, and Al₂O₃) in the direct vapor upgrading of beechwood biomass vapors via a two-stage process comprising a non-catalytic hydropyrolysis step followed by ex-situ catalytic upgrading. The performance of metal oxides was compared with non-metal oxide such as SiO₂. Through extensive characterization (H₂-TPR, NH₃-TPD, O₂-TPD, CO₂-TPD, BET, XRD, and Pyridine-FTIR), we establish that the combination of high weak acidity, low strong basicity, and reducibility of TiO₂ results in superior catalytic performance. Ex-situ upgrading over TiO₂ achieves the lowest oxygen-to-carbon ratio (O/C = 0.09) in bio-oil, the highest C₂+ fraction (98.7 %), and the largest C8-C16 fraction (49.9 %), while minimizing light molecule formation (16.5 %). Binding energy analyses further reveal that weak adsorption of model compounds (acetone, acetic acid, guaiacol) occurs on the TiO₂ (101) surface compared to other oxide surfaces, highlighting its exceptional properties for deoxygenation and C–C coupling. This work establishes the first comprehensive correlation between the catalytic performance of oxide supports and their surface properties using actual biomass feedstock, thus offering valuable insights for designing advanced catalysts for biomass upgrading.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"452 ","pages":"Article 116435"},"PeriodicalIF":6.5,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145072098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pyroelectric–photothermal synergy dynamically modulates interfacial electric field in Ag-BiOI/BiOIO3-Nx heterojunctions for enhanced antibiotic degradation","authors":"Xiaobao Chen ,&nbsp;Meng Liu ,&nbsp;Yu Liu ,&nbsp;Sijian Liu ,&nbsp;Xiaoping Li ,&nbsp;Zonghan Huang ,&nbsp;Lanxuan Wen ,&nbsp;Rongwei Li ,&nbsp;Shengjiong Yang ,&nbsp;Dahu Ding ,&nbsp;Bo Wang ,&nbsp;Rongzhi Chen","doi":"10.1016/j.jcat.2025.116434","DOIUrl":"10.1016/j.jcat.2025.116434","url":null,"abstract":"<div><div>Although the static interfacial electric field (IEF) within the heterojunction enables directional photocharge transfer, the accumulated carriers shield the space charge region (SCR), thereby hindering photocharge separation. To address this, we introduce a dynamic IEF modulation strategy via Pyroelectric–photothermal synergy in Ag-BiOI/BiOIO₃-N<em>_x</em> heterojunctions (ABBN<em>_x</em>), which effectively enhances the photocharge separation and photocatalytic activity. Specifically, the reaction rate constant (0.0179 min⁻¹) for tetracycline (TC) degradation and photocurrent density (9.03 uA/cm²) of ABBN₂ were 2.67 and 2.91 times higher than those of pristine BiOIO₃, respectively. Experimental findings demonstrated that the surface plasmon resonance (SPR) of Ag nanoparticles markedly improved photothermal conversion efficiency, while N doping in the BiOIO₃ lattice increased the polarization effect of IO₃ pyramids, thereby boosting pyroelectric performance. The heat generated by Ag nanoparticles through photothermal conversion induces a transient polarization electric field in BiOIO₃-N<em>_x</em>, which effectively disrupts the charge balance in the SCR, and thus ensures the continuous separation of photocharges by IEF. This work offers new insights into antibiotic wastewater treatment and the dynamic modulation of the IEF structure in photocatalytic systems.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"452 ","pages":"Article 116434"},"PeriodicalIF":6.5,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145072097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atomic-level engineering of metal–metal interaction in intermetallic catalysts for efficient propene hydroformylation","authors":"Shuai Cui ,&nbsp;Enze Xu ,&nbsp;Lei Wang ,&nbsp;Xin Song ,&nbsp;Kelong Liu ,&nbsp;Na Liu ,&nbsp;Xiaolong Yan ,&nbsp;Mingyao Li ,&nbsp;Yusen Yang ,&nbsp;Min Wei","doi":"10.1016/j.jcat.2025.116431","DOIUrl":"10.1016/j.jcat.2025.116431","url":null,"abstract":"<div><div>Hydroformylation, a pivotal industrial reaction heavily reliant on Rh-based catalysts, remains limited by Rh scarcity and cost. While Co-based catalysts are potential alternatives, they still face dual challenges of insufficient activity and stability. In this work, Co-based intermetallic catalysts (CoMoIMC and CoWIMC) were synthesized through a layered double hydroxide precursor strategy. During propylene hydroformylation, CoMoIMC exhibited a butyraldehyde production rate of 105.6 mmol·g⁻¹·h⁻¹ (97 % selectivity) with &gt;90 % activity retention over 10 cycles under mild conditions (140 °C, 4.5 MPa), outperforming conventional CoAl₂O₃ by 2.4-fold. Reactant-TPD experiments and DFT calculations revealed that the ordered Co₃Mo/Co₃W structures altered CO adsorption from hollow to top sites, reducing the desorption energy from 29.7 to 19.7 kJ·mol⁻¹ and lowering the CO insertion barrier from 1.28 to 1.09 eV. This work proposes a new strategy for preparing highly active and stable non-noble metal hydroformylation catalysts, which has a promising potential for industrial applications.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"452 ","pages":"Article 116431"},"PeriodicalIF":6.5,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145068132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dual mechanisms synergistically activating methane and inhibiting overoxidation over ZnO prepared under magnetic field","authors":"Zhongxuan Yin ,&nbsp;Weixin Li ,&nbsp;Qing Liu ,&nbsp;Yongqing Ma ,&nbsp;Ganhong Zheng ,&nbsp;Chuhong Zhu ,&nbsp;Meiling Wang","doi":"10.1016/j.jcat.2025.116425","DOIUrl":"10.1016/j.jcat.2025.116425","url":null,"abstract":"<div><div>Photocatalytic oxidation of methane (CH₄) to value added liquid C1 products offers a promising way for utilizing the abundant CH₄ resource, nevertheless, suffering from poor products formation rate and peroxidation. Here, a kind of ZnO-0.4 catalyst with oxygen vacancy (O_v) is prepared under magnetic field for photooxidation CH₄ to C1 products with yield rate and selectivity of 13.6 mmol g⁻¹ and 100 %. No peroxide products such as CO_x were produced even under 8 h of light exposure. Mechanism research indicates that O_v in the catalyst acts as reactive site, facilitates CH₄ activation through both h⁺ and adsorbed-O₂ (via formation of Zn–O⋯O–Zn) routes. The two CH₄ activation routes proceed simultaneously, which results in promoted charge separation and enhanced catalytic efficiency. This work provides a new approach for the design and preparation of noble metal-free CH₄ conversion catalysts.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"452 ","pages":"Article 116425"},"PeriodicalIF":6.5,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145056932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electronic structure modulation of schwertmannite by interfacial chemical bond for enhanced photo-Fenton catalytic activity","authors":"Xuqian Wang,&nbsp;Zhe Wang,&nbsp;Tianyu Wang,&nbsp;Anqi Wang,&nbsp;Jiepeng Wang,&nbsp;Yongkui Zhang,&nbsp;Yabo Wang","doi":"10.1016/j.jcat.2025.116426","DOIUrl":"10.1016/j.jcat.2025.116426","url":null,"abstract":"<div><div>The rational design of Fe-based catalysts with optimized electronic structures remains critical for achieving efficient pollutant degradation in photo-Fenton systems. This study presents a facile biomineralization approach to structurally modulate biogenic schwertmannite (Sch, Fe₈O₈(OH)_8-2x(SO₄)_x, 1 ≤ x ≤ 1.75) through xanthan gum (XG) addition. The abundant carboxyl group on XG provided well-dispersed nucleation sites, which modulated the growth of Sch crystal clusters and effectively transformed aggregated Sch particles into nanowhisker-embedded hybrid network (Sch-XG) with 9.6-fold increased specific surface area. Moreover, strong interfacial chemical-bonded of Fe-O-C bridge was proved to exist between surface iron species of Sch and carboxyl group of XG, which further changed the energy band and electronic structure of Sch. Eventually, such modification facilitated photogenerated electron transfer, Fe(III)/Fe(II) cycling and enhanced adsorption-activation of H₂O₂ by Sch-XG hybrid, which demonstrated good photo-Fenton performance, achieving complete sulfamethoxazole (SMX) removal within 20 min (<em>k</em> = 0.179 min⁻¹) through synergistic radical-nonradical pathways dominated by surface-bound •OH. Notably, the Sch-XG hybrid exhibited broad pH adaptability (3.0–9.0), low iron leaching (&lt;0.37 mg L⁻¹), and &gt;99 % SMX degradation efficiency after fourth cycles. After degradation products identification and ROS attack sites analysis, three primary SMX transformation routes via hydroxylation, ring opening and S-N bond cleavage were proposed, while effective detoxification of SMX was achieved through toxicity prediction and bio-toxicity assessment. This work provided a feasible interfacial engineering strategy to enhance catalytic potential of natural iron minerals for sustainable water remediation.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"452 ","pages":"Article 116426"},"PeriodicalIF":6.5,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145056849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"One-pot template-free green synthesis of mesoporous amorphous silica-alumina for enhanced hydrogen storage in naphthalene","authors":"Dongze Li ,&nbsp;Zhentao Liu ,&nbsp;Liang Qiao ,&nbsp;Xiaoyang Kong ,&nbsp;Enhua Wang ,&nbsp;Haidong Li ,&nbsp;Lili Jin ,&nbsp;Chunya Wang ,&nbsp;Chunming Xu ,&nbsp;Xilong Wang","doi":"10.1016/j.jcat.2025.116411","DOIUrl":"10.1016/j.jcat.2025.116411","url":null,"abstract":"<div><div>Amorphous silica-alumina (ASA) with ultra-high specific surface area and suitable pore structure was successfully synthesized through the development of a cost-effective and efficient one-pot synthesis method under template-free conditions. Then Pt-loaded ASA catalysts with suitable acidity and highly dispersed Pt species were prepared via a synergistic strategy combining surface modification and “soft” nitriding. Among the as-designed Pt-loaded ASA catalysts, Pt/ASA catalyst prepared via boron modification and “soft” nitriding (Pt/BNASA) demonstrated outstanding naphthalene hydrogenation performance, achieving complete naphthalene conversion (100 %) and full decalin selectivity (100 %), along with a reaction rate constant (<em>k</em>) of 16.4 × 10⁻⁶ mol g⁻¹ s⁻¹ and a turnover frequency (<em>TOF</em>) value of 2415 h⁻¹. The superior naphthalene hydrogenation activity and selectivity of Pt/BNASA catalyst could be attributed to the combination of the excellent textural properties, and the optimized balance between acidic sites and metallic sites.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"452 ","pages":"Article 116411"},"PeriodicalIF":6.5,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145043228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chemical recycling of polyethylenes with low gas products by catalytic hydrogenolysis with heterogeneous CeO2-supported Cu-doped Ru catalyst","authors":"Masazumi Tamura,&nbsp;Yuna Sasano,&nbsp;SMA Hakim Siddiki,&nbsp;Masato Akatsuka,&nbsp;Pengru Chen,&nbsp;Yusuke Kita","doi":"10.1016/j.jcat.2025.116417","DOIUrl":"10.1016/j.jcat.2025.116417","url":null,"abstract":"<div><div>Chemical recycling of polyolefins to valuable chemicals has a high potential to mitigate plastic problems and contributes to carbon recycling. In the previous works, we reported that CeO₂- and ZrO₂-supported Ru (Ru/CeO₂ and Ru/ZrO₂) catalysts were effective for the hydrogenolysis of polyolefins such as PE, PP, and even waste PE plastics; however, the gas products were formed in ∼10 % yield. The development of effective heterogeneous catalysts that can suppress the formation of cheap gas products, particularly methane, through the incorporation of inexpensive metals into Ru is highly required to achieve high yields of valuable chemicals such as liquid and waxes. Herein, we found that 1 wt% Cu doped 1 wt% Ru/CeO₂, Cu(1)-Ru(1)/CeO₂, was an effective heterogeneous catalyst for the suppression of the methane formation (2.3 %, C1–C4 gas: ∼4%) at &gt;99 % conversion in the hydrogenolysis of LDPE at 5 MPa H₂, providing the high yield (96 %) of the valuable chemicals (liquid chemicals (C5-C21) + waxes (C ≥22)). The gas selectivity remains low even at a low H₂ pressure of 2 MPa. Based on the catalyst characterizations such as XRD, TEM, TEM-EDX, H₂-TPR, XAS, and FT-IR analyses, the size of the active metal particles over Cu(1)-Ru(1)/CeO₂ catalyst is about 1 nm, and the addition of Cu metal into Ru/CeO₂ formed Ru-Cu surface alloy on the Ru particles. The formation of the small metal particles and Cu-Ru surface alloy by the addition of inexpensive Cu to Ru decreased the Ru ensemble size to suppress the consecutive C–C bond dissociation of LDPE, leading to low methane and gas yields.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"452 ","pages":"Article 116417"},"PeriodicalIF":6.5,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145043682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Alkanol dehydration and dehydrogenation pathways on anatase TiO2 under oxidative and nonoxidative conditions","authors":"Manasi Vyas,&nbsp;Lynsey Patterson,&nbsp;Stephanie Kwon","doi":"10.1016/j.jcat.2025.116414","DOIUrl":"10.1016/j.jcat.2025.116414","url":null,"abstract":"<div><div>Alkanol dehydration offers a promising route for converting biomass-derived short-chain oxygenates into alkenes, which are valuable industrial intermediates. Titanium dioxide (TiO₂) has been extensively studied for this reaction due to its high activity and low cost. However, the inherent heterogeneity of commercially available TiO₂ has led to conflicting reports on reactivity and product selectivity, further complicated by the diverse reaction conditions employed in previous studies. This work aims to update our understanding of alkanol reactions on anatase TiO₂ by integrating transient, titration, kinetic, and spectroscopic methods, using 2-propanol and 1-propanol as model reactants. Under anerobic conditions, 2-propanol primarily undergoes dehydration to form propene and water. A minor pathway forms acetone via nonoxidative dehydrogenation, but only after an induction period during which surface oxygen vacancies accumulate. Notably, propene formation rates remain largely constant, even as acetone formation rates decrease by ∼60 % during the initial induction period. These transient behaviors, together with pretreatment and characterization data, suggest that dehydration predominantly occurs on smaller TiO₂ crystallites that provide most of the surface area, whereas dehydrogenation is favored on larger crystallites with smaller band gap energies. In situ pyridine titration was used to quantify the number of active sites for each pathway, enabling accurate turnover rate normalization. Detailed kinetic analysis showed that both dehydration and nonoxidative dehydrogenation are inhibited by 2-propanol, water, and 2-propanol–water dimers, but to different extents. The rate constant for nonoxidative dehydrogenation reflects a significantly lower activation enthalpy than that for the oxidative route; however, this is offset by a large entropic penalty, resulting in higher free energy barriers at relevant temperatures and thus a lower overall rate constant. This kinetic framework offers mechanistic insight into the temperature- and pressure-dependent shifts in reaction rates and product selectivity, while also reconciling prior discrepancies reported in the literature.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"452 ","pages":"Article 116414"},"PeriodicalIF":6.5,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145043680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}