Objective In order to study the catalyst mechanism of titanium dioxide sulfur recovery catalyst for Claus reaction process, the adsorption performance of the catalyst for hydrogen sulfide, sulfur dioxide and organic sulfur was studied.

Methods Aiming at the adsorption and desorption of reactants and products involved in Claus chemical reaction on typical titanium dioxide catalyst, the adsorption properties of H₂S and SO₂ products under single and co-existing conditions and the adsorption properties of water vapor and sulfur dioxide products and the adsorption performance of water vapor and sulfur vapor products were studied by microreactor and mass spectrometry.

Results Under the typical operating conditions of the 1st-order Claus reactor, both hydrogen sulfide and sulfur dioxide could be strongly adsorbed on the titanium dioxide catalyst, in which the adsorption of sulfur dioxide was stronger than that of hydrogen sulfide, and the saturated adsorption capacity of the former was 3.3 times that of the latter. When the reactants and products both existed, the adsorption of the catalyst for hydrogen sulfide and sulfur dioxide would decrease, and the adsorption of sulfur vapor was stronger than that of water vapor. However, after deducting the adsorption amount produced by capillary condensation of sulfur vapor, the blocking effect of water vapor on Claus reaction was stronger than that of sulfur vapor.

Conclusions The titanium dioxide catalyst developed based on the research results had been applied in three sets of sulfur recovery units. The results showed that the hydrolysis effect of organic sulfur was remarkable, and the hydrolysis rates of COS and CS₂ were more than 90%.