Coordination-Modulated Al ₂ O ₃ Nanowire Catalysts for COS Hydrolysis: Promoting Mechanism of Al Electron Localization

Al2O3 catalysts have been widely applied in the field of COS hydrolysis. However, the inferior low-temperature activity and insufficient stability limit its further application. Moreover, the coordination regulation strategy of Al sites and the optimization mechanism of the hydrolysis reaction still need to be explored in depth. In this paper, an Al2O3 nanowire catalyst derived from NH4Al(OH)2CO3 was synthesized. The preferred ACCH-K0.1Al2O3 catalyst achieved more than 80% COS conversion at 75 °C and WHSV of 120,000 cm–3g–1h–1. The characterization results demonstrated that the elevated proportion of unsaturated coordinated Al3+ and doped K optimized the electron density of the Al sites, increased the surface −OH concentration, and constructed asymmetric oxygen vacancies, which enhanced the adsorption and activation ability of COS. In situ DRIFTS and theoretical calculations results verified that electron localization contributed to the preferred bond cleavage of COS and reduced the overall reaction energy barrier, which in turn promoted the catalytic hydrolytic activity at low temperatures. This investigation presents a reliable perspective and theoretical basis for the regulation of the Al coordination environment and the study of the reaction mechanism.