Syngas Production From Ethanol Dry Reforming Over Cu-based Catalysts

The purpose of this article is to study syngas production from ethanol dry reforming over Cu-based catalysts in order to convert undesirable greenhouse gas CO₂ to high-valued chemicals.Herein,the effect of support type on the activity and stability of the catalyst was deeply investigated.Moreover,both the key physicochemical properties and morphology structure of the as-prepared catalysts before and after the reaction were characterized by a series of technique including X-ray diffraction?XRD?,high resolution transmission electron microscopy?HRTEM?,scanning electron microscopy?SEM?,inductively coupled plasma ICP?ICP?,Raman spectroscopy?Raman?,specific surface area measurement?BET?and temperature programmed reduction/oxidation?TPR/TPO?.The relationship between catalyst structure and performance was established in combination with the characterization and experimental results.This might provide the meaningful introduction on the development of high efficient catalysts for CO₂ chemical conversion.Firstly,Cu-based catalysts supported on different materials?CeO₂,ZrO₂,CeO₂-ZrO₂?were prepared by co-precipitation method with urea.And the characterization results revealed that the key features such as the redox ability,the metal-support interaction as well as the dispersion of active Cu species decreased in the following order:CuCeZr>CuCe>Cu/Zr.It was generally accepted that the above features played an important role in adsorption/activation of reactants and the product distribution.CuCeZr catalyst exhibited better catalytic activity and stability than that of other samples?CuCe,CuZr?,which evidenced the effect of supports.Typically,over CuCeZr catalyst,the formed syngas ratio under the stoichiometric feed composition was close to theoretical 1/1?H₂/CO?.CuCeZr sample also showed excellent stability and no obvious deactivation was observed after 90h time on stream in 700?.Noticeably,the strong Cu-support interaction not only facilitated ethanol adsorption and the intermediates diffusion but greatly hindered the sintering of active Cu metal during the reaction process.In addition,the higher dispersion of Cu species for CuCeZr catalyst was also favorable to prevent the sintering of Cu species under the high temperature reaction atmosphere.The large amount of O vacancies as evidenced by Raman characterization might efficiently activate CO₂ molecule to form active O species,which was beneficial for the insitu remove of the formed coke over catalyst surface in order to improve catalyst stability.