Amine-functionalized sepiolite: Toward highly efficient palladium nanocatalyst for dehydrogenation of additive-free formic acid

Abstract

Formic acid has recently come to be considered as a promising material for chemical storage of hydrogen. To date, highly efficient and low-cost heterogeneous catalysts for formic acid dehydrogenation without additive under mild conditions are still limited. In this work, we employed amine-functionalized sepiolite, a typical natural clay mineral with fibrous structure, as support to synthesize a nanocatalyst by the simple impregnation-reduction method. The amine groups on amine functionalized sepiolite support are shown to significantly reduce the average size of Pd nanoparticles (from 7.60 to 2.80 nm) as well as provide a synergistic effect with the Pd nanoparticles, which boosts the rate of additive-free formic acid dehydrogenation (initial turnover frequency (TOF) values of 5587 h−1 at 60 °C, equal to or even better than the most active heterogeneous catalysts). Compared to current catalyst systems, this catalyst can lead to a brighter prospect of cost-efficient heterogeneous catalysts for formic acid dehydrogenation.