{"title":"Modulating the chemical environment of Ni2+ for the oxidative dehydrogenation of ethane: The formation of LAS(Al3+/Ga3+)-Ni-OH site","authors":"Qinghui Li, Huahua Zhao, Jian Yang, Jun Zhao, Liang Yan, Huanling Song, Lingjun Chou","doi":"10.1016/j.cej.2024.156939","DOIUrl":null,"url":null,"abstract":"The oxidative dehydrogenation of ethane to ethylene (ODHE) usually suffers from the issues of ethane conversion-ethylene selectivity seesaw. Herein, a series of alumina-supported Ni and Ga catalysts with different molar ratios of Ni to Ga were synthesized by facile impregnation method constructing the Lewis acid site (LAS) strategy to obtain great ethylene selectivity (97 %). The variation of Ni:Ga ratio adjusted the ionic substitution ability, redox ability and acidity, thus regulate the chemical environment of Ni<sup>2+</sup> to the formation of LAS(Al<sup>3+</sup>/Ga<sup>3+</sup>)-Ni-OH structure, which was proposed to be the active site for selective oxidation of ethane to ethylene, as proved by H<sub>2</sub>-TPR, ToF-SIMS, quasi in-situ XPS and in-situ FTIR. Moreover, the probable mechanism of ODHE reaction was proposed that C<sub>2</sub>H<sub>6</sub> molecules were mainly adsorbed on LAS sites and activated on Ni-OH site of the catalyst. The pulse test further suggested that O<sup>-</sup> was mainly associated with the generation of CO<sub>2</sub> and Ni<sup>(2-n)+</sup> was connected with the production of CH<sub>4</sub>. It is highlighted that adjusting the Ni-related species and oxygen species on the catalyst surface are crucial to further improve the ethylene selectivity.","PeriodicalId":270,"journal":{"name":"Chemical Engineering Journal","volume":null,"pages":null},"PeriodicalIF":13.3000,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemical Engineering Journal","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1016/j.cej.2024.156939","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
引用次数: 0
Abstract
The oxidative dehydrogenation of ethane to ethylene (ODHE) usually suffers from the issues of ethane conversion-ethylene selectivity seesaw. Herein, a series of alumina-supported Ni and Ga catalysts with different molar ratios of Ni to Ga were synthesized by facile impregnation method constructing the Lewis acid site (LAS) strategy to obtain great ethylene selectivity (97 %). The variation of Ni:Ga ratio adjusted the ionic substitution ability, redox ability and acidity, thus regulate the chemical environment of Ni2+ to the formation of LAS(Al3+/Ga3+)-Ni-OH structure, which was proposed to be the active site for selective oxidation of ethane to ethylene, as proved by H2-TPR, ToF-SIMS, quasi in-situ XPS and in-situ FTIR. Moreover, the probable mechanism of ODHE reaction was proposed that C2H6 molecules were mainly adsorbed on LAS sites and activated on Ni-OH site of the catalyst. The pulse test further suggested that O- was mainly associated with the generation of CO2 and Ni(2-n)+ was connected with the production of CH4. It is highlighted that adjusting the Ni-related species and oxygen species on the catalyst surface are crucial to further improve the ethylene selectivity.
期刊介绍:
The Chemical Engineering Journal is an international research journal that invites contributions of original and novel fundamental research. It aims to provide an international platform for presenting original fundamental research, interpretative reviews, and discussions on new developments in chemical engineering. The journal welcomes papers that describe novel theory and its practical application, as well as those that demonstrate the transfer of techniques from other disciplines. It also welcomes reports on carefully conducted experimental work that is soundly interpreted. The main focus of the journal is on original and rigorous research results that have broad significance. The Catalysis section within the Chemical Engineering Journal focuses specifically on Experimental and Theoretical studies in the fields of heterogeneous catalysis, molecular catalysis, and biocatalysis. These studies have industrial impact on various sectors such as chemicals, energy, materials, foods, healthcare, and environmental protection.