Ultrafine PdAg alloy nanoparticles anchored on NH2-functionalized 2D/2D TiO2 nanosheet/rGO composite as efficient and reusable catalyst for hydrogen release from additive-free formic acid at room temperature

A 2D-2D titanium dioxide nanosheet-reduced graphene oxide (TNS-rGO) composite with better electronic conductivity and hydrophilicity was prepared by the hydrothermal method. The as-obtained TNS-rGO composite was further functionalized with 3-aminopropyltriethoxysilane (APTES) to provide a large amount of –NH2 groups on the surface for anchoring ultrafine PdAg alloy nanoparticles with an average particle size of 1.69 nm by a facile wet reduction approach. Benefiting from the combined effects of well-dispersed PdAg alloy nanoparticles, facilitated electron transfer from TNS-rGO to Pd, and increased electron density of active sites, the Pd8Ag1/NH2-TNS-rGO catalyst exhibited excellent activity towards dehydrogenation of formic acid without adding any additives at 298 K, corresponding to an initial turn over frequency as high as 1090 h−1, which is much higher than that of most other state-of-the-art catalysts.