Journal of Natural Gas Chemistry最新文献

{"title":"CF4 decomposition over solid ternary mixture NaF-Si-MO (MO = La2O3, CeO2, Pr6O11, Nd2O3, Y2O3)","authors":"Yanfei Pan,&nbsp;Xianjun Niu,&nbsp;Yanan Wang,&nbsp;Xiufeng Xu","doi":"10.1016/S1003-9953(11)60341-1","DOIUrl":"10.1016/S1003-9953(11)60341-1","url":null,"abstract":"<div><p>A solid ternary mixture consisting of NaF, silicon and one metal oxide such as La2O3, CeO2, Pr₆O₁₁, Nd2O3, and Y2O3 was prepared and used as de-fluorinated reagent for CF4 decomposition. The results show that 90% conversion of CF4 can be reached initially over NaF-Si-La2O3, NaF-Si-CeO2, NaF-Si-Nd2O3, and NaF-Si-Y2O3 at 850 °C. The fresh and used reagents were characterized using XRD and XPS techniques. It was found that the active components of NaF and metal oxides in NaF-Si-CeO2, NaF-Si-Pr₆O₁₁, NaF-Si-Nd2O3, and NaF-Si-Y2O3 were transformed into inert phases of mixed metal fluorides and silicates, respectively, resulting in an ineffective utilization of these de-fluorinated reagents, whereas no inert phases from NaF and La2O3 can be observed in the used NaF-Si-La2O3, indicating the NaF-Si-La2O3 reagent could be utilized more efficiently than the other reagents in CF4 decomposition.</p></div>","PeriodicalId":56116,"journal":{"name":"Journal of Natural Gas Chemistry","volume":"21 2","pages":"Pages 109-112"},"PeriodicalIF":0.0,"publicationDate":"2012-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1003-9953(11)60341-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56790961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of support nature (γ-Al2O3 and SiO2-Al2O3) on the performances of rhenium oxide catalysts in the metathesis of ethylene and 2-pentene","authors":"Weena Phongsawat ,&nbsp;Benjamas Netiworaruksa ,&nbsp;Kongkiat Suriye ,&nbsp;Siraprapha Dokjampa ,&nbsp;Piyasan Praserthdam ,&nbsp;Joongjai Panpranot","doi":"10.1016/S1003-9953(11)60348-4","DOIUrl":"10.1016/S1003-9953(11)60348-4","url":null,"abstract":"<div><p>The metathesis of ethylene and 2-pentene was studied as an alternative route for propylene production over Re₂O₇/γ-Al₂O₃ and Re₂O₇/SiO₂-Al₂O₃ catalysts. Both NH₃ temperature-programmed desorption (NH₃-TPD) and H₂ temperature-programmed reduction (H₂-TPR) results showed that Re₂O₇/SiO₂-Al₂O₃ exhibited stronger acidity and weaker metal-support interaction than Re₂O₇/γ-Al₂O₃. At 35–60 °C, isomerization free metathesis was observed only over Re₂O₇/γ-Al₂O₃, suggesting that the formation of metal-carbene metathesis active sites required only weak acidity. Our results suggest that on the Re₂O₇/SiO₂-Al₂O₃, hydrido-rhenium species ([Re]-H) were formed in addition to the metathesis active sites, resulting in the isomerization of the initial 1-butene product into 2-butenes. A subsequent secondary metathesis reaction between these 2-butenes and the excess ethylene could explain the enhanced yields of propylene observed. The results demonstrate the potential for high yield of propylene from alternative feedstocks.</p></div>","PeriodicalId":56116,"journal":{"name":"Journal of Natural Gas Chemistry","volume":"21 2","pages":"Pages 158-164"},"PeriodicalIF":0.0,"publicationDate":"2012-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1003-9953(11)60348-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56791666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Bi promoter on the performances of selective oxidation of isobutane to methacrolein over MoVO/AlPO4 catalysts","authors":"Xitao Wang ,&nbsp;Mei Li ,&nbsp;Fen Wang ,&nbsp;Shunhe Zhong ,&nbsp;Shi Jiang ,&nbsp;Sihe Wang","doi":"10.1016/S1003-9953(11)60349-6","DOIUrl":"10.1016/S1003-9953(11)60349-6","url":null,"abstract":"<div><p>The effects of Bi on the catalytic performance of selective oxidation of isobutane to methacrolein over MoVO/AlPO₄ catalyst were investigated by XRD, FT-Raman, XPS, UV-vis DRS techniques. The results show that the addition of Bi component into the MoVO/AlPO₄ catalyst obviously improves the catalytic performance, and the selectivity to methacrolein can increase from 14.2% to 45.1% with the increase of Bi/V molar ratio from 0 to 1. Combining the characterization results with the reaction evaluation, it is concluded that the catalytic activities of the MoV_0.3Bi_<em>x</em>/AlPO₄ catalysts are related to the crystalline phase composition and the dispersion of molybdenum and vanadium oxides species in general, and also to the V⁵⁺/V⁴⁺ molar ratio on the surface in particular.</p></div>","PeriodicalId":56116,"journal":{"name":"Journal of Natural Gas Chemistry","volume":"21 2","pages":"Pages 165-169"},"PeriodicalIF":0.0,"publicationDate":"2012-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1003-9953(11)60349-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56791768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CO2 reforming of methane over nickel catalysts supported on nanocrystalline MgAl2O4 with high surface area","authors":"Narges Hadian ,&nbsp;Mehran Rezaei ,&nbsp;Zeinab Mosayebi ,&nbsp;Fereshteh Meshkani","doi":"10.1016/S1003-9953(11)60355-1","DOIUrl":"10.1016/S1003-9953(11)60355-1","url":null,"abstract":"<div><p>In this paper dry reforming of methane (DRM) was carried out over nanocrystalline MgAl₂O₄-supported Ni catalysts with various Ni loadings. Nanocrystalline MgAl₂O₄ spinel with high specific surface area was synthesized by a co-precipitation method with the addition of pluronic P123 triblock copolymer as surfactant, and employed as catalyst support. The prepared samples were characterized by X-ray diffraction (XRD), N₂ adsorption, H₂ chemisorption, temperature-programmed reduction (TPR), temperature-programmed oxidation (TPO), temperature-programmed desorption (TPD) and transmission and scanning electron microscopies (TEM, SEM) techniques. The obtained results showed that the catalyst support has a nanocrystalline structure (crystal size: about 5 nm) with a high specific surface area (175 m²·g⁻¹) and a mesoporous structure. Increasing in nickel content decreased the specific surface area and nickel dispersion. The prepared catalysts showed high catalytic activity and stability during the reaction. SEM analysis revealed that whisker type carbon deposited over the spent catalysts and increasing in nickel loading increased the amount of deposited carbon. The nickel catalyst with 7 wt% of nickel showed the highest catalytic activity.</p></div>","PeriodicalId":56116,"journal":{"name":"Journal of Natural Gas Chemistry","volume":"21 2","pages":"Pages 200-206"},"PeriodicalIF":0.0,"publicationDate":"2012-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1003-9953(11)60355-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56791844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Zr/Ti molar ratio in SO2−4/ZrO2-TiO2 calcined at different temperatures on its surface properties and glucose reactivity in near-critical methanol","authors":"Lincai Peng ,&nbsp;Junping Zhuang ,&nbsp;Lu Lin","doi":"10.1016/S1003-9953(11)60346-0","DOIUrl":"10.1016/S1003-9953(11)60346-0","url":null,"abstract":"<div><p>Effects of Zr/Ti molar ratio in SO²⁻₄/ZrO₂-TiO₂ solid acid catalyst calcined at different temperatures on its surface properties and catalytic activity were thoroughly investigated in this paper. The physicochemical characteristics of prepared samples were determined by N2 adsorptiondesorption, XRD, NH3-TPD and XPS techniques, respectively. It was found that the crystallization temperature of the samples increased after the combination of ZrO₂ and TiO₂; and phase transformations from the anatase to the rutile of TiO₂ species and the tetragonal to the monoclinic of ZrO₂ species were effectively suppressed at higher temperature. The sample with a Zr/Ti molar ratio of 3/1 calcined at 450 °C showed the highest surface area and the most acid sites among all the tested samples. The acid site densities of samples were relatively closed to each other if they were calcined at the same temperature, however, decreased with the calcination temperature. The result indicates that the sulfur content in samples is a crucial factor to control the acid site density. Calcining the sample at 650 °C and higher temperatures resulted in a significant desorption of sulfate ion on the samples. The synthesized samples were evaluated as a potential catalyst for glucose conversion under the near-critical methanol conditions (200 °C/4 MPa). The results suggested that the relatively weaker acid sites of the catalyst were more favorable for the accumulation of methyl glucosides, while the moderate acid sites were responsible for the formation of methyl levulinate. The catalytic activity for methyl levulinate production almost increases linearly with the catalyst acid site density. The catalyst deactivation is due to the loss of sulfate ion and the two catalysts with Zr/Ti molar ratios of 3/1 and 1/3 could effectively alleviate the deactivation caused by sulfate solution in the reaction medium and can be reused after calcination with the reuse rate of over 90% in terms of the methyl levulinate selectivity.</p></div>","PeriodicalId":56116,"journal":{"name":"Journal of Natural Gas Chemistry","volume":"21 2","pages":"Pages 138-147"},"PeriodicalIF":0.0,"publicationDate":"2012-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1003-9953(11)60346-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56791244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of aluminum modification on catalytic properties of PtSn-based catalysts supported on SBA-15 for propane dehydrogenation","authors":"Yongzheng Duan,&nbsp;Yuming Zhou,&nbsp;Yiwei Zhang,&nbsp;Xiaoli Sheng,&nbsp;Shijian Zhou,&nbsp;Zewu Zhang","doi":"10.1016/S1003-9953(11)60356-3","DOIUrl":"10.1016/S1003-9953(11)60356-3","url":null,"abstract":"<div><p>The catalytic properties of PtSn-based catalysts supported on siliceous SBA-15 and Al-modified SBA-15, such as Al-incorporated SBA-15 (A1SBA-15) and alumina-modified SBA-15 (AI₂O₃/SBA-15), for propane dehydrogenation were investigated. AI₂O₃/SBA-15 was prepared either by an impregnation method using aluminum nitrate aqueous solution, or by the treatment of SBA-15 with a Al(OC₃H₇)₃ solution in anhydrous toluene. N₂-physisorption, FT-IR spectroscopy, solid-state ²⁷Al MAS NMR spectroscopy, hydrogen chemisorption, XRF, NH₃ temperature-programmed desorption, X-ray photoelectron spectroscopy and TPO were used to characterize these samples. Among these catalysts, the PtSn-based catalyst supported on AI₂O₃/SBA-15, which was grafted with Al(OC₃H₇)₃, exhibited the best catalytic performance in terms of activity and stability The possible reason was due to the high Pt metal dispersion and/or the strong interactions among Pt, Sn, and the support.</p></div>","PeriodicalId":56116,"journal":{"name":"Journal of Natural Gas Chemistry","volume":"21 2","pages":"Pages 207-214"},"PeriodicalIF":0.0,"publicationDate":"2012-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1003-9953(11)60356-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56792022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preparation of LaFe0.95Pd0.05O3 perovskites and their catalytic performances in methane combustion","authors":"Xiaojing Zhang,&nbsp;Yong Li,&nbsp;Huaju Li,&nbsp;Wenjie Shen","doi":"10.1016/S1003-9953(11)60342-3","DOIUrl":"10.1016/S1003-9953(11)60342-3","url":null,"abstract":"<div><p>The physic-chemical properties of LaFe_0.95Pd_0.05O₃ perovskites were strongly dependent on the temperature of calcination. Most of the organic substances and inorganic impurities were readily removed at 723 K but single-phase and well crystallized perovskite structure was formed at 873 K. With further raising the calcination temperature, the crystallite size of LaFe_0.95Pd_0.05O₃ increased considerably. The LaFe_0.95Pd_0.05O₃ sample that calcined at 1073 K showed only comparable activity as the reference LaFeO₃ catalyst, in particular below 923 K, but pretreatment with the reaction gas at 1223 K resulted in significantly enhanced activity due to the generation of active PdO species on the surface. The hysteresis feature upon heating-cooling cycle further confirmed the strong interaction between Pd and LaFeO₃ in the perovskite structure.</p></div>","PeriodicalId":56116,"journal":{"name":"Journal of Natural Gas Chemistry","volume":"21 2","pages":"Pages 113-118"},"PeriodicalIF":0.0,"publicationDate":"2012-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1003-9953(11)60342-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56791078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An accurate empirical correlation for predicting natural gas compressibility factors","authors":"Ehsan Sanjari,&nbsp;Ebrahim Nemati Lay","doi":"10.1016/S1003-9953(11)60352-6","DOIUrl":"10.1016/S1003-9953(11)60352-6","url":null,"abstract":"<div><p>The compressibility factor of natural gas is an important parameter in many gas and petroleum engineering calculations. This study presents a new empirical model for quick calculation of natural gas compressibility factors. The model was derived from 5844 experimental data of compressibility factors for a range of pseudo reduced pressures from 0.01 to 15 and pseudo reduced temperatures from 1 to 3. The accuracy of the new empirical correlation has been compared with commonly used existing methods. The comparison indicates the superiority of the new empirical model over the other methods used to calculate compressibility factor of natural gas with average absolute relative deviation percent (AARD%) of 0.6535.</p></div>","PeriodicalId":56116,"journal":{"name":"Journal of Natural Gas Chemistry","volume":"21 2","pages":"Pages 184-188"},"PeriodicalIF":0.0,"publicationDate":"2012-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1003-9953(11)60352-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56791568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative study between gas phase and liquid phase for the production of DMC from methanol and CO2","authors":"Ahmed Aouissi,&nbsp;Salem S. Al-Deyab","doi":"10.1016/S1003-9953(11)60353-8","DOIUrl":"10.1016/S1003-9953(11)60353-8","url":null,"abstract":"<div><p>Direct synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide over Co_1.5PW₁₂O₄₀ in liquid and in gas phase is investigated. The synthesized catalyst has been characterized by means of FTIR and XRD. Liquid phase experiment results showed that high pressures are favorable for the synthesis of DMC. However, DMC formation is limited by the reaction with co-produced water. DMC selectivity is more strongly dependent on the temperature than on the pressure of CO₂. As for the reactions in gas phase, it has been found that both CH3OH conversion and DMC selectivity decreased with increasing temperature, owing to the decomposition of DMC at high temperatures. High temperatures and more amount of Co_1.5PW₁₂O₄₀ catalyst favor the formation of dimethoxymethane (DMM) and methyl formate (MF).</p></div>","PeriodicalId":56116,"journal":{"name":"Journal of Natural Gas Chemistry","volume":"21 2","pages":"Pages 189-193"},"PeriodicalIF":0.0,"publicationDate":"2012-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1003-9953(11)60353-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56791640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Decomposition of methylamine on Mo(100) surface: A DFT study","authors":"Jianhong Liu,&nbsp;Cunqin Lü,&nbsp;Dongli Du,&nbsp;Yong Guo","doi":"10.1016/S1003-9953(11)60345-9","DOIUrl":"10.1016/S1003-9953(11)60345-9","url":null,"abstract":"<div><p>The initial decomposition of methylamine on Mo(100) surface has been investigated by self-consistent (GGA-PW91) density functional theory combined with periodic slab model. The adsorption energies of possible species and the activation energies for possible elementary reactions involved are obtained in the present work. Our results indicate that the barriers decreased with the order of C–N&lt;N–H&gt;C–H. In addition, metastable adsorption of the abstracted hydrogen atom on the hollow site in the final state is also considered for the N–H and C–H bond breaking. For the C–H bond cleavage, the reaction barrier that the abstracted hydrogen located on the hollow site in the final state is lower than that on the bridge site. However, for the N–H bond breaking, the barriers are alike for the abstracted hydrogen on both hollow and bridge sites in the final state.</p></div>","PeriodicalId":56116,"journal":{"name":"Journal of Natural Gas Chemistry","volume":"21 2","pages":"Pages 132-137"},"PeriodicalIF":0.0,"publicationDate":"2012-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1003-9953(11)60345-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56791124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}