Coordination and K-induced electronic effects promote efficient COS hydrolysis over K-Nd/Al2O3 catalysts

A K-Nd/Al 2 O 3 catalyst achieves a COS capacity of 1.46 g/g under H 2 S/O 2 co-feeding. • K modulates Nd Lewis acidity and facilitates the dissociative activation of H 2 O. • Synergistic K and Nd sites enable the formation of key *HOCOS and *HSCOO intermediates. • Adaptive Nd-O x sites, enhanced by K-induced effects, promote H 2 S desorption. The development of efficient alumina-based catalysts for carbonyl sulfide (COS) hydrolysis remains a significant challenge, as their application in real blast furnace gas is largely hindered by insufficient activity and poor long-term durability. Here, K-Nd/Al 2 O 3 maintains nearly complete COS conversion for 20 h at 120 °C and achieves a cumulative COS conversion capacity of 1.46 g/g under a simplified H 2 S/O 2 -containing atmosphere. Comprehensive characterization reveals that K-Nd co-modulation tailors acid-base site distribution, preserving active sites. Aberration-corrected HAADF-STEM and XAFS analyses confirm that Nd is predominantly atomically dispersed, existing as isolated, low-coordinated Nd-O x single-sites. During reaction, the Nd-O coordination number increases from 4.2 to 8.0 without aggregation, demonstrating reaction-induced reconstruction of the first coordination shell. Surface characterization, in-situ DRIFTS, and DFT calculations further show that K enhances surface electron density and fine-tunes Nd Lewis acidity, promoting H 2 O dissociation and nucleophilic *OH attack on COS, stabilizing *HOCOS and *HSCOO intermediates while facilitating H 2 S desorption. The synergy between Nd-O x centers and K-induced electronic regulation reconcile durable COS hydrolysis under harsh conditions. Download: Download high-res image (225KB) Download: Download full-size image