Trivalent‑chromium-modified palladium catalyst supported on carbon quantum dots for rapid hydrogen production from formic acid.

Metal oxide promoters are commonly employed to enhance catalytic efficiency by electronically modulating the active metal centers of catalytic materials. In this paper, a palladium (Pd)-based catalyst modified with amorphous chromium(III) oxide (CrO) and supported on nitrogen-doped carbon quantum dots (NCDs) was prepared for efficient catalytic formic acid dehydrogenation (FAD). The abundant surface functional groups of the NCDs effectively anchor the metallic Pd, while the confinement effect arising from the crosslinking of NCDs helps inhibit metal particle aggregation. Notably, the incorporation of CrO simultaneously enriches the electron density in the vicinity of Pd and enhances the electron-donating capability of the electron-rich nitrogen atoms toward Pd. As a result, without using any additives, this catalyst exhibited exceptional catalytic FAD performance at 323 K, with a turnover frequency of 724 h and an activation energy of 40.9 kJ·mol. This study proposes a rational strategy for the design of FAD catalysts with enhanced metal electron density and strengthened metal-support interaction via the incorporation of amorphous metal oxides.