Shuzhen Lyu, Li Wang, Ruichen Liu, Rongrong Zhang, Guozhu Liu
{"title":"Intermetallic PdZn Supported on Porous Carbon Derived from ZIF-8 for Efficient Direct Synthesis of H2O2","authors":"Shuzhen Lyu, Li Wang, Ruichen Liu, Rongrong Zhang, Guozhu Liu","doi":"10.1021/acssuschemeng.5c00132","DOIUrl":null,"url":null,"abstract":"Design of highly efficient Pd-based catalysts for the direct synthesis of hydrogen peroxide (DSHP) from H<sub>2</sub> and O<sub>2</sub> still remains a challenge. Herein, Zn-doped porous carbon was synthesized via pyrolysis of ZIF-8 under a N<sub>2</sub> atmosphere and then applied as supports of Pd catalysts for DSHP. The results of aberration corrected HAADF-STEM, XRD, XPS, and TEM reveal that the Zn species in the porous carbon support exist mainly in highly dispersed ZnN<sub><i>x</i></sub>. In the reduction process, Zn atoms are first reduced by spillover hydrogen from adjacent Pd<sup>0</sup> atoms and then diffuse into Pd particles to form intermetallic PdZn. The pyrolysis temperature appears to be a crucial factor affecting the proportion of PdZn. A catalyst supported on the porous carbon obtained at a pyrolysis temperature of 850 °C has the highest proportion of PdZn (Pd/ZnC-850). The DFT simulations reveal that intermetallic PdZn shifts the <i>d</i>-band center of Pd atoms away from the Fermi level; weakens the adsorption of O<sub>2</sub>, *OOH, and H<sub>2</sub>O<sub>2</sub>; and shortens the length of the O–O bonds of *OOH and H<sub>2</sub>O<sub>2</sub>. These are favorable for inhibiting cleavage of O–O bonds. Pd/ZnC-850 exhibits a superior H<sub>2</sub>O<sub>2</sub> selectivity (89.6%), relatively high H<sub>2</sub> conversion, and good stability. A H<sub>2</sub>O<sub>2</sub> productivity of 44,396 mol kg<sub>Pd</sub><sup>–1</sup> h<sup>–1</sup> is achieved.","PeriodicalId":25,"journal":{"name":"ACS Sustainable Chemistry & Engineering","volume":"86 1","pages":""},"PeriodicalIF":7.1000,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"ACS Sustainable Chemistry & Engineering","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1021/acssuschemeng.5c00132","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
Intermetallic PdZn Supported on Porous Carbon Derived from ZIF-8 for Efficient Direct Synthesis of H2O2
Design of highly efficient Pd-based catalysts for the direct synthesis of hydrogen peroxide (DSHP) from H2 and O2 still remains a challenge. Herein, Zn-doped porous carbon was synthesized via pyrolysis of ZIF-8 under a N2 atmosphere and then applied as supports of Pd catalysts for DSHP. The results of aberration corrected HAADF-STEM, XRD, XPS, and TEM reveal that the Zn species in the porous carbon support exist mainly in highly dispersed ZnNx. In the reduction process, Zn atoms are first reduced by spillover hydrogen from adjacent Pd0 atoms and then diffuse into Pd particles to form intermetallic PdZn. The pyrolysis temperature appears to be a crucial factor affecting the proportion of PdZn. A catalyst supported on the porous carbon obtained at a pyrolysis temperature of 850 °C has the highest proportion of PdZn (Pd/ZnC-850). The DFT simulations reveal that intermetallic PdZn shifts the d-band center of Pd atoms away from the Fermi level; weakens the adsorption of O2, *OOH, and H2O2; and shortens the length of the O–O bonds of *OOH and H2O2. These are favorable for inhibiting cleavage of O–O bonds. Pd/ZnC-850 exhibits a superior H2O2 selectivity (89.6%), relatively high H2 conversion, and good stability. A H2O2 productivity of 44,396 mol kgPd–1 h–1 is achieved.
期刊介绍:
ACS Sustainable Chemistry & Engineering is a prestigious weekly peer-reviewed scientific journal published by the American Chemical Society. Dedicated to advancing the principles of green chemistry and green engineering, it covers a wide array of research topics including green chemistry, green engineering, biomass, alternative energy, and life cycle assessment.
The journal welcomes submissions in various formats, including Letters, Articles, Features, and Perspectives (Reviews), that address the challenges of sustainability in the chemical enterprise and contribute to the advancement of sustainable practices. Join us in shaping the future of sustainable chemistry and engineering.