Al_2O_3负载Cu,Fe或Ni掺杂氧化钼催化乙苯氧化脱氢(英文)  

Cu, Fe, or Ni doped molybdenum oxide supported on Al_2O_3 for the oxidative dehydrogenation of ethylbenzene

作　　者：Tiago Pinheiro Braga Ant?nio Narcísio Pinheiro Edson R.Leite Regina Cláudia R.dos Santos Antoninho Valentini 

机构地区：[1]LABPEMOL-Laboratório de Peneiras Moleculares, Institute of Chemistry, Federal University of Rio Grande do Norte [2]Department of Chemistry, Federal University of S?o Carlos [3]Langmuir-Laboratório de Adsor??o e Catálise, Department of Analytical Chemistry and Physical Chemistry, Federal University of Ceará

出　　处：《催化学报》2015年第5期712-720,共9页

基　　金：scholarships from CNPq and CAPES

摘　　要：Molybdenum-based catalysts supported on Al_2O_3 doped with Ni, Cu, or Fe oxide were synthesized and used in ethylbenzene dehydrogenation to produce styrene. The molybdenum oxide was supported using an unconventional route that combined the polymeric precursor method(Pechini) and wet impregnation on commercial alumina. The samples were characterized by X-ray diffraction(XRD), N_2 adsorption-desorption isotherms, temperature-programmed reduction of H_2(H_2-TPR),and thermogravimetric(TG) analysis. XRD results showed that the added metals were well dispersed on the alumina support. The addition of the metal oxide(Ni, Cu, or Fe) of 2 wt% by wet impregnation did not affect the texture of the support. TPR results indicated a synergistic effect between the dopant and molybdenum oxide. The catalytic tests showed ethylbenzene conversion of 28%–53% and styrene selectivity of 94%–97%, indicating that the addition of the dopant improved the catalytic performance, which was related to the redox mechanism. Molybdenum oxides play a fundamental role in the oxidative dehydrogenation of ethylbenzene to styrene by its redox and acid–base properties. The sample containing Cu showed an atypical result with increasing conversion during the reaction, which was due to metal reduction. The Ni-containing solid exhibited the highest amount of carbon deposited, shown by TG analysis after the catalytic test, which explained its lower catalytic stability and selectivity.Molybdenum-based catalysts supported on Al2O3 doped with Ni, Cu, or Fe oxide were synthesized and used in ethylbenzene dehydrogenation to produce styrene. The molybdenum oxide was sup-ported using an unconventional route that combined the polymeric precursor method （Pechini） and wet impregnation on commercial alumina. The samples were characterized by X-ray diffraction （XRD）, N2 adsorption-desorption isotherms, temperature-programmed reduction of H2 （H2-TPR）, and thermogravimetric （TG） analysis. XRD results showed that the added metals were well dis-persed on the alumina support. The addition of the metal oxide （Ni, Cu, or Fe） of 2 wt% by wet im-pregnation did not affect the texture of the support. TPR results indicated a synergistic effect be-tween the dopant and molybdenum oxide. The catalytic tests showed ethylbenzene conversion of 28%-53% and styrene selectivity of 94%-97%, indicating that the addition of the dopant improved the catalytic performance, which was related to the redox mechanism. Molybdenum oxides play a fundamental role in the oxidative dehydrogenation of ethylbenzene to styrene by its redox and acid-base properties. The sample containing Cu showed an atypical result with increasing conver-sion during the reaction, which was due to metal reduction. The Ni-containing solid exhibited the highest amount of carbon deposited, shown by TG analysis after the catalytic test, which explained its lower catalytic stability and selectivity.

关 键 词：氧化铝载体 乙苯脱氢 铁氧化物 氧化脱氢 钼氧化物 镍掺杂 氧化还原机理 金属氧化物 

分 类 号：O625.12[理学—有机化学]