Impact of preparation methods on the performance of Cu/Ni/Zr catalysts for methanol decomposition

Abstract

Utilizing waste heat from engine exhausts to decompose methanol into a hydrogen (H2) and carbon monoxide (CO) mixture, subsequently reintroduced into the engine, offers a significant potential to enhance engine efficiency and reduce emissions. The efficacy of the catalyst is crucial, as it directly influences the composition of the decomposition gases, thereby impacting energy conservation and emissions reduction. This study investigates the impact of various preparation methods for the self-developed Cu/Ni/Zr catalyst for methanol hydrogenation decomposition. These techniques include the co-precipitation method, co-impregnation method, and citrate complexation method, evaluated within a temperature spectrum of 220 °C–320 °C. Employing analytical methods such as x-ray Photoelectron Spectroscopy (XPS), x-ray Diffraction (XRD), Thermogravimetric Analysis-Differential Scanning Calorimetry (TGA-DSC), Brunauer–Emmett–Teller (BET), Temperature-Programmed Reduction (TPR), and Scanning Electron Microscopy (SEM) analysis, the study elucidates the mechanism of methanol decomposition catalyzed by Cu/Ni/Zr. The findings indicate that the catalyst’s activity, in terms of decomposition rate and hydrogen content, ranks in descending order from the co-impregnation method, followed by the citrate complexation method, to the co-precipitation method.