Exploring N-Containing Compound Catalyst for H 2 S Selective Oxidation: Case Study of TaON and Ta 3 N 5

In addition to traditional metal oxides, N-containing compound would become efficient catalyst for H 2 S selective oxidation. TaON and Ta 3 N 5 , taking as examples, with porous structure are able to selectively oxidize H 2 S into sulfur. TaON exhibits ca. 99% H 2 S conversion and ca. 89% sulfur selectivity at 250 ℃, while Ta 3 N 5 exhibits near complete H 2 S conversion (~ 100%) and 86% sulfur selectivity at 250 ℃. TaON of lower N content shows higher sulfur selectivity (~ 90–100%) above 130 ℃, compared with that (~ 86–95%) over Ta 3 N 5 . Whereas, Ta 3 N 5 of higher N content demonstrates higher H 2 S conversion (~ 30–40%) below 160 ℃, compared with that (~ 6–30%) over TaON. Temperature programmed desorption results show that Ta 3 N 5 owns larger amount of acid sites and weaker basic sites than TaON. Over Ta 3 N 5 , the reactant molecules could dissociatively adsorb on acid sites more frequently and could be easier to move across the weaker basic sites, thus increasing probability for reaction at low temperature. Manipulating both cations and anions in N-containing compound can alter surface property for optimization of selective H 2 S oxidation. Graphic Abstract