NiO lattice oxygen overflow promoted by Ti3C2 support enhances catalytic hydrolysis of carbonyl sulfide in metallurgical gas

Achieving efficient hydrolysis of carbonyl sulfide (COS) on catalysts at moderate temperature, while suppressing the production of sulfate and carbon, remains a daunting challenge. Herein, NiO/Ti 3 C 2 MXene composites were prepared for the catalytic hydrolysis of COS at moderate temperature based on DFT simulation calculations that indicate the catalytic system of lattice oxygen activation-migration is conducive to COS hydrolysis. The NiO/Ti 3 C 2 exhibited a prominent COS hydrolysis activity compared to the pure NiO. Based on various characterizations and DFT calculations, a proton capture strategy for enhanced COS hydrolysis activity was proposed. The existence of a strong electronic interaction between NiO and Ti 3 C 2 activates the adjacent Ni-O bond at the interface, and makes the surface top-Ni active sites fully exposed under CO atmosphere. These top-Ni species accelerate the dissociation of H 2 O into ∗H, and facilitates protons transport to the intermediate ∗SH, thereby promoting the formation of H 2 S and the entire hydrolysis process. This proton capture strategy may provide help for the preparation of various high-performance catalysts for diverse hydrogenation reactions even beyond COS hydrolysis.