Immobilization of ultrafine bimetallic nanocatalysts on metal–organic framework-derived N-doped nanoporous carbon/manganese oxide for efficient hydrous hydrazine decomposition

Abstract

Developing low-cost nanocatalysts with high performance for the selective decomposition of hydrous hydrazine is desirable but remains a critical challenge. Herein, manganese oxide-modified bimetallic Ni_0.4Rh_0.6 nanoparticles (NPs) immobilized on N-doped carbon (MnO_x–Ni_0.4Rh_0.6@NC) were facilely obtained via a conventional wet chemical co-reduction, with NH₂-UiO-66 serving as a precursor to fabricate the solid support NC after controlled pyrolysis. The obtained MnO_x–Ni_0.4Rh_0.6@NC exhibited extraordinarily high catalytic activity as well as 100% H₂ selectivity for the selective dehydrogenation of hydrous hydrazine, giving a turnover frequency value (TOF) as high as 1363 h⁻¹ at 323 K. The efficient catalytic activity was mainly attributed to the small size effect and the strong synergistic interaction between the metal NPs and the solid support, resulting in an electronic redistribution of active sites. In addition, the MnO_x possessed abundant “dangling bonds”, providing abundant unsaturated coordination bonds and facilitated optimized electronic reconfiguration, which enhanced the kinetics of hydrogen production. This work offers a new strategy for designing bimetallic nanosystems with high catalytic performance, holding promise for tremendous industrial applications in the future.