Multi-phase coexisting metal oxide derived by MOFs for the CO-SCR reaction at low temperature and in situ DRIFTS study on reaction mechanism

Abstract

Nowadays the air pollution caused by NO and CO needs to be solved urgently. Precious metal catalyst has good activity but is expensive. Transition metal oxide catalyst is low in cost, and support transition metal oxide can improve the catalytic activity. The metal oxides synthesized by traditional methods often have uneven loading due to their irregular morphology and small pore size. So we select MOFs with abundant pore structures and controllable morphologies as the carriers. This paper Cu-BTC (BTC is trimellitic acid radical) as the template was loaded with different proportions of Co by impregnation method, and then heterogeneous commensal metal oxide containing carbon skeleton with regular morphology, excellent performance and stability were prepared by calcination. Samples were characterized by SEM, EDX, TEM, TG, XRD, H2-TPR, XPS, BET and in situ DRIFTS. The pyrolysis of cobalt-loaded CuBTC resulted in the multi-phase coexisting metal oxide of CuO, Cu2O and Co3O4, with a highly dispersed carbon on the surface of the catalysts. The carbon containing lone electrons could promote the electron transfer between Cu and Co, thus improving the catalytic activity. The best catalytic ability was Co0.75-CuOx/C, and reaction mechanism on it was E-R mechanism (≤200 ℃) and L-H mechanism (225–300 ℃).