Operando x-ray absorption spectroscopy of Ce promoted CuZn/gamma-Al2O3 in the COx/H2 hydrogenation

Copper-based materials, known for CO hydrogenation, convert syngas (COx/H2) to methanol. With γ-Al2O3 as a dehydration catalyst, the methanol is further dehydrate into dimethyl ether. The introduction of cerium oxide as an electron promoter improves feed gas conversion efficiency. However, the electronic structure dynamics involving Ce species in the Cu-Zn/γ-Al2O3 system remain inadequately understood. This research aims to elucidate the effects of varied cerium loadings in xCe-10Cu5ZnO/γ-Al2O3 (x=0, 1, 3, 5, 7) on covalence changes and coordination numbers. Using Operando X-ray Absorption Spectroscopy (XAS), we will probe the electronic structure through XANES and EXAFS of the Ce-CuZnO/γ-Al2O3 system. Insights from Ce L2,3 XANES and Cu-Zn K-edge will establish a structure-activity relationship. Concurrently, temperature-driven spectroscopy and syngas ratio effects in catalysis will be studied, enabling a detailed interpretation of the catalytic mechanism.