Quenching-Induced Surface Engineering of Copper-Based Catalysts for Enhanced Methanol Steam Reforming

Abstract

Methanol steam reforming (MSR) presents a promising pathway for hydrogen production in fuel cells. However, the rational selection and design of catalysts continue to pose significant challenges. Herein, we demonstrate a facile and novel quenching technique that simultaneously realizes the desired surface metal doping and vacancy production, thereby modulating the local electronic structure and coordination environments at/near the CuO surface. Meanwhile, the ultrafine CeO2 particles formed on the CuO surface can effectively inhibit the sintering growth of Cu species during the MSR reaction, which provide the function of a longer service time. Consequently, the quenching-derived catalyst (Ce/CuO-Q) attains 100% methanol conversion with 0.208% CO selectivity at 260 °C, exhibiting higher catalytic activity and lower CO selectivity compared with the control catalyst (Ce/CuO-R) prepared using the conventional impregnation approach. After 100 h of operation, methanol conversion of the structured Ce/CuO-Q catalyst decreases to 92.3% with 0.168%−0.236% CO selectivity, indicating the good catalytic durability. Additionally, Fourier transform infrared spectroscopy elucidates the evolution of reactants and intermediates on the catalyst surface. Importantly, the quenching technique has been successfully applied to other rare earth salt solution systems, including La/CuO-Q, Y/CuO-Q, Nd/CuO-Q, and Gd/CuO-Q catalysts, which also exhibit excellent catalytic activity in the MSR reaction. This study offers new inspiration for developing high-performance and durable metal oxide nanocatalysts.