Cr-modified CeMo/SiO2 as the efficient and stable supported catalyst for dehydrogenation of methanol to anhydrous formaldehyde

Direct dehydrogenation of methanol to co-produce hydrogen and formaldehyde represents a promising chemical technology for generating clean fuel and critical chemical intermediates. However, the harsh reaction conditions pose significant challenges in developing efficient and durable catalysts for this process. In this research, Cr-modified CeMo/SiO₂ supported catalyst (Cr-Ce₁Mo₆/SiO₂) that achieves exceptional performance in methanol-to-anhydrous-formaldehyde conversion is reported. Strategic Cr doping with optimal metal loading and Ce/Mo ratio introduces customized oxygen vacancies, which is beneficial for catalytic kinetics. In addition, the interplay between Cr and Mo species not only weakens surface acidity but concurrently reinforces the Brønsted acid characteristics of Mo^6 + centers. This dual functionality facilitates rapid desorption of carbon-containing intermediates during catalytic cycles, thereby mitigating surface coking and suppressing the reductive deactivation of high-valence Mo species. The achieved acid activity control/high-speed desorption/anti-coke synergy establishes a self-sustaining beneficial cycle that perpetuates catalytic efficiency. This synergistic mechanism fundamentally underpins the exceptional catalytic performance and long-term durability of the material. The optimized catalyst delivers 89.6 % methanol conversion with 92.9 % formaldehyde selectivity at 300 ℃. Remarkably, it retains 85.7 % conversion and 89.0 % selectivity over 240 h of continuous operation. This study effectively optimized the directional activity and durability of the supported catalyst through ingenious modification strategy, providing valuable insights for direct dehydrogenation of methanol and other similar catalytic processes.