Solution combustion synthesis of CoSx, MoSx, CoSx-MoSx and their catalytic activity in H2 production from H2S decomposition

Abstract

Production of hydrogen from H2S is desirable and can meet partly the ever-increasing demand on cheaper and greener hydrogen as a cleaner energy resource since it makes better use of H2S than the various Claus processes. Medium temperature effective catalysts for H2S decomposition would help developing a sulfur looping process to overcome the thermodynamic limitation for H2S decomposition. However, developing such medium temperature catalyst for direct H2S decomposition is still a great challenge. This work adapts solution combustion synthesis (SCS) method to synthesize oxide and sulfide of molybdenum and cobalt with fine crystalline and their activities in H2S decomposition were investigated. The in-situ sulfurization with thiourea in SCS process leads to higher surface area and higher activity of the resultant catalysts. The presence of CoSx enchances the activity of MoSx in H2S decomposition. The H2S decomposition activity of the CoSx-MoSx composite is higher than that of each single component one. The H2S decomposition kinetics analysis shows that an activation energy of 43.3 kJ/mol was achieved on 20%CoSx-MoSx which is much lower than that reported in literatures.