Trimetallic nanoparticles: Synthesis, characterization and catalytic degradation of formic acid for hydrogen generation

摘要

Pd-Ag-Fe, Fe-Pd-Ag and Fe-Ag-Pd trimetallic nanoparticles were synthesized by seedless and step-wise simultaneous chemical reduction of Fe3+, Ag+ and Pd2+ by using hydrazine in presence of cetyltrimethylammonium bromide and used as a catalyst for the degradation of formic acid. The effects of nanoparticle composition, presence of sodium format (promoter), [catalyst], [formic acid] and temperature play key roles in the hydrogen generation. The Ba(OH)(2) trap experiment and water displacement technique were used to determine the generation of CO2 and H-2, respectively. The decomposition of formic acid followed complex-order kinetics with respect to [formic acid]. It was found that Fe-Ag-Pd showed a maximum catalytic activity (turn over frequency) of 75 mol H-2 per mol catalyst per h. The activation energy (E-a = 51.6 kJ/mol), activation enthalpy (Delta H = 48.9 kJ/mol) and activation entropy (Delta S = 151.0 JK-1 moll were determined and discussed for the catalytic reaction. The reusability of the Fe-Ag-Pd at 50 degrees C shows an efficient degree of activity for six consecutive catalytic cycles. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.