Robust Hydrogen Production from Additive-Free Formic Acid via Mesoporous Silica-Confined Pd-ZrO2 Nanoparticles at Room Temperature

Hydrogen (H-2) is becoming the most promising candidate for the future sustainable energy systems because it is clean and regenerable. Formic acid (FA, HCOOH), one of the high-value products of the biological metabolic process and the reduction of carbon dioxide (CO2), is considered to be the most efficient hydrogen supplier because it is nontoxic and easy to store and transport and has high hydrogen content. Herein, Pd-ZrO2 nanoparticles (NPs) immobilized in amine-modified mesoporous silica (Pd-ZrO2/SBA-15-NH2) with ultrasmall particle size (1.5 nm) and high dispersion are successfully prepared and applied as an effective catalyst toward the additive-free dehydrogenation of FA at ambient conditions. As a result of the synergistic electronic effects of Pd and ZrO2, the strong interaction between the Pd-ZrO2 NPs and SBA-15-NH2 substrates and the abundant basic sites originated from ZrO2 and -NH2 groups, the as-prepared Pd-ZrO2/SBA-15-NH2 catalyst possesses 100% hydrogen selectivity as well as unexpected catalytic performance with a high turnover frequency value of 1408 h(-1) toward CO-free hydrogen production from FA at 298 K, which is even better than most of the effective Pd-based heterogeneous catalysts ever reported. This work offers insights into the facile and controllable synthesis strategy of metal-MOx/support systems for high-efficiency dehydrogenation of chemical hydrides.

Automated summary

Hydrogen is promising for future sustainable energy systems due to its cleanliness and renewability, while formic acid is considered an efficient hydrogen supplier because of its high hydrogen content and ease of storage and transport. Researchers have successfully developed Pd-ZrO2/SBA-15-NH2 catalyst for the dehydrogenation of formic acid, achieving 100% hydrogen selectivity at ambient conditions.