Work

Dual modification of gallium‐doped Silicalite‐1 via alkaline treatment for exceptional methane to formic acid oxidation

Year: 2026

Type: article

Abstract: The selective oxidation of methane to value‐added oxygenates under mild conditions is hindered by its inert C‐H bond and the over‐oxidation. Herein, we report a dual‐modification strategy combining gallium incorporation with alkaline hydrothermal treatment to enhance Fe dispersion and tailor acidity in a Silicalite‐1 zeolite. The resulting 0.5Fe/Ga‐S‐1‐Hydrothermal Treatment (HTS) catalyst delivers a formic acid (FA) yield of 58,851 μmol g cat −1 h −1 with 90.3% liquid‐product selectivity at 70°C using H 2 O 2 as the oxidant, cycling stability. Characterizations reveal that Ga doping promotes moderate acid sites, while alkaline treatment drives the redispersion of aggregated iron oxide clusters into dispersed, isolated extra‐framework Fe 3+ species, the key active centers. Electron paramagnetic resonance and in situ Fourier Transform Infrared Spectroscopy (FTIR) support a radical‐mediated pathway involving ·OH, ·OOH, and ·CH 3 intermediates drive the oxidation of methane to FA. This work demonstrates that integration of heteroatom doping and post‐synthetic treatment offers a platform for designing high‐performance zeolite catalysts for methane valorization.

Source: AIChE Journal

DOI: 10.1002/aic.70691