The nitriding of titanium silicate-1 and its effect on gas-phase epoxidation of propylene

The nitrogen-containing titanium silicate-1 (N-TS-1) was synthesized to improve the catalytic performance of Au/N-TS-1 in gas-phase epoxidation of propylene. The nitrogen content has an important influence on the activity of the catalyst and can be controlled by adjusting the nitriding temperature and the nitriding time. The propylene oxide (PO) formation rate was promoted from 78.7 g_PO/h/kg_Cat of Au/TS-1 to 138.7 g_PO/h/kg_Cat of Au/N-TS-1 (nitrided at the optimal condition). It was found that the ligand effect of terminal-NH₂ caused by nitrogen enrichment increased the Au capture efficiency and the gold loading. And the reduction in the acid amount on the surface of the molecular sieve caused by nitridation reduced the adsorption of PO on the surface of the support.