Silica Supported Ternary Nirupt Alloy Nanoparticles: Highly Efficient Heterogeneous Catalyst for H2 Generation Via Selective Decomposition of Hydrous Hydrazine in Alkaline Solution

Abstract

Hydrous hydrazine (H2NNH2 center dot H2O, HH) is taken notice to be one of the promising hydrogen storage materials for the future due to its high hydrogen content of 7.9% wt. In this study, we develop a new catalytic material formed from trimetallic NiRuPt alloy nanoparticles decorated on silica support (NiRuPt/SiO2) for the hydrogen production via selective decomposition of HH under mild reaction conditions. NiRuPt/SiO2 catalyst was prepared by wet-impregnation technique in water at room conditions and characterized by the various spectroscopic/analytical tools. The sum of their results is revealing that the formation ternary NiRuPt alloy (d(mean) = 6.4 nm) nanoparticles on the surface of SiO2. The prepared new catalytic system eases the selective hydrogen production from decomposition of HH in aqueous alkaline solution with high activity (324.1 min(-1)) and conversion (>99%) at 333 K. Furthermore, painless recovery plus high durability of these supported NiRuPt nanoparticles against to agglomeration and leaching make them recyclable catalyst so that they retain >70% of their activity at 5th reuse and the ex-situ generated NiRuPt/SiO2 catalyst was found to provide total turnover number (TTON) 4181 in the complete decomposition of HH over 11.4 h before deactivation in the complete decomposition of HH. The studies addressed herein also includes the collection of kinetic records for NiRuPt/SiO2 catalyzed decomposition of HH in alkaline solution depending on catalyst [NiRuPt], substrate [H2NNH2 center dot H2O], promoter [NaOH] concentrations and temperature to determine the rate expression and the activation parameters (Ea, Delta H#, and Delta S#) of the catalytic reaction. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.