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通过一系列原位、非原位表征,包括透射电子显微镜(TEM)、傅里叶变换红外光谱(FTIR)、程序升温解吸/还原/氧化(TPD/TPR/TPO)、X射线光电子能谱(XPS)等,系统地研究了Pd/FeOx催化剂的逆水煤气变换反应(RWGS).以Pd(acac)2为前驱体合成了高度分散的Pd/FeOx催化剂,在400℃下,RWGS的CO2转化率高达29％,CO选择性超过98％,在目前文献中报道的催化剂中处于领先水平.通过原位表征方法,我们进一步研究了Pd/SiO2和Pd-Fe/SiO2,并明确指出了Pd-FeOx界面对促进RWGS反应的重要作用.准原位XPS实验进一步揭示了Pd/FeOx界面上动态形成的Pdδ+-Fe2+物种是高效催化C=O离解的活性位点.因此,实验结果证明,反应过程中动态形成的Pdδ+-Fe2+界面可以显著提高RWGS的活性和选择性,对CO2吸附、C=O解离和CO脱附都起到的促进作用.“,”We systematically investigated Pd/FeOx for the reverse water gas shift(RWGS)reaction using a combina-tion of ex situ and in situ characterizations,including transmission electron microscopy(TEM),Fourier-transform infrared(FTIR)spectroscopy,temperature-programmed desorption/reduction/oxidation(TPD/TPR/TPO),and X-ray photoelectron spectroscopy(XPS).A highly dispersed Pd/FeOx catalyst was synthesized using Pd(acac)2 as the pre-cursor.The catalyst exhibited high activity,with CO2 conversion of～29％and CO selectivity ogreater than 98％at 400 ℃,which are among the highest values in the literature.Moreover,Pd/SiO2 and Pd-Fe/SiO2 were further studied to determine the significant role of the Pd-FeOx interface in promoting the RWGS reaction.Semi-in situ XPS revealed the dynamic formation of Pdδ+-Fe2+species at the Pd-FeOx interface;the species acted as highly active sites for CO2 dissociation.Our results also showed the formation of the Pdδ+-Fe2+interface during the RWGS reaction remarkably enhanced the activity and selectivity of the Pd-FeOx catalyst for the reaction,benefiting CO2 adsorption,C = O dissociation,and CO desorption.