NiPt Nanoparticles Anchored onto Hierarchical Nanoporous N-Doped Carbon as an Efficient Catalyst for Hydrogen Generation from Hydrazine Monohydrate

摘要

Catalytic decomposition of the hydrogen-rich hydrazine monohydrate (N2H4 center dot H2O) represents a promising hydrogen storage/production technology. A rational design of advanced N2H4 center dot H2O decomposition catalysts requires an overall consideration of intrinsic activity, number, and accessibility of active sites. We herein report the synthesis of a hierarchically nanostructured NiPt/N-doped carbon catalyst using a three-step method that can simultaneously address these issues. The chelation of metal precursors with polydopamine and thermolysis of the resulting complexes under reductive atmosphere resulted in a concurrent formation of N-doped carbon substrate and catalytically active NiPt alloy nanoparticles. Thanks to the usage of a silica nanosphere template and dopamine precursor, the N-doped carbon substrate possesses a hierarchical macroporous-mesoporous architecture. This, together with the uniform dispersion of tiny NiPt nanoparticles on the carbon substrate, offers opportunity for creating abundant and accessible active sites. Benefiting from these favorable attributes, the NiPt/N-doped carbon catalyst enables a complete and rapid hydrogen production from alkaline N2H4 center dot H2O solution with a rate of 1602 h(-1) at 50 degrees C, which outperforms most existing catalysts for N2H4 center dot H2O decomposition.