Work

Reversed TiOx Layer-Induced Strong Metal–Support Interactions on Ni/Ti–SiO2 Catalysts for Propene Epoxidation with H2 and O2

Year: 2025

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide Direct propene epoxidation using H 2 and O 2 to produce propylene oxide (PO) is considered an environmentally friendly and revolutionary industrial process. With the necessity of finding alternatives to precious Au-based catalysts, there is a critical need for highly active nonprecious metal catalysts in epoxidation reactions. Herein, we successfully constructed different degrees of strong metal–support interaction (SMSI) by reversing TiO 2 islands into TiO x layers over Ni nanoparticles in a H 2 atmosphere. The resulting nonprecious 1.27%Ni/Ti–SiO 2 catalyst with moderate SMSI exhibited a remarkable 90.6% selectivity toward PO with a formation rate of 9.23 g PO h –1 g Ni –1 . Mechanistic investigations revealed that tetrahedral-Ti sites and Ni–TiO x overlayers synergistically catalyze propene epoxidation with H 2 and O 2 . The Ni–TiO x interface provided abundant unsaturated Ti (TiO x ) sites, enhancing the adsorption capacity of propene and consequently accelerating subsequent propene epoxidation with in situ synthesized H 2 O 2 . This study introduces an original approach for the utilization of nonprecious metal catalysts in gas-phase propene epoxidation, with promising implications for advancing industrial olefin epoxidation processes.

Source: ACS Catalysis

DOI: 10.1021/acscatal.5c02681