Low-temperature hydrolysis of carbonyl sulfide in blast furnace gas using Al2O3-based catalysts with high oxidation resistance

Abstract

Water vapor, O2 and various sulfides in blast furnace gases affect the carbonyl sulfide (COS) hydrolysis reaction. In this study, we investigated the hydrolysis and deactivation mechanisms of a series of catalysts that were synthesized by depositing K2O and MoO3 on industrial alumina-based catalysts. Alumina nanosheets were deposited with potassium oxide, in which MoO3 nanoparticles were incorporated resulting in needle-like structures. The modified catalysts had substantially enhanced COS hydrolysis activity at low temperatures. The introduction of K2O and MoO3 significantly increased the number of weakly basic sites on the catalysts and reduced the lattice oxygen content. The catalysts exhibited high oxidation resistance and hydrolysis properties. According to the poisoning mechanism, the deposition of sulfate species tended to reduce weakly basic sites. High-valent Mo easily excited the adsorbed H2O on the catalysts, producing –OH groups that facilitated the COS hydrolysis reaction. This modification facilitates the further investigation of catalysts capable of promoting COS hydrolysis and their application in the manufacturing industry.