Highly Dispersed Pt/γ-Al2O3/Al Structured Mesh-Type Catalysts Prepared by Competitive Adsorption Method Applied in Catalytic Hydrogen Combustion: Start-up Performance and Mass Transfer Enhancement

The increasing utilization of hydrogen fuel cells underscores the growing significance of addressing the issue of hydrogen (H₂) leakage. Catalytic hydrogen combustion (CHC) is widely considered as an exceptionally promising safety measure due to its ability to mitigate the release of H₂ at 25 ℃. A high dispersion mesh-type Pt/γ-Al₂O₃/Al catalyst was prepared using the competitive adsorption method, which found that the particle size of platinum (Pt) was constrained by the spatial constraint effect of lactic acid. Compared with the conventional impregnation method, the addition of lactic acid promoted the migration of Pt into the γ-Al₂O₃/Al pore channels, as a result, the particle size of Pt was reduced from 5.8 to 3.3 nm when lactic acid increased to 0.15 mol/L. It can be demonstrated that catalysts with smaller Pt particle size starts within 5 min in CHC reaction, which is 1/9 of that of the catalyst with large Pt particles. In contrast to granular catalysts, the effect of diffusion in the CHC reaction was effectively reduced by mesh structure, thus facilitating the rapid removal of reaction-generated water from the catalyst surface. This resulted in the combination of reactor macroscale flow and transfer with the surface interface of catalytically active components.

Graphical abstract