Synthesis of hydroxylamine sulfate via NO hydrogenation over Pt/Graphite catalysts. Part 3: Functionalization of the support surface and formation of the active component during the catalyst synthesis

The peculiarities of formation of platinum nanoparticles and chemical coating of carbon support surface during preparation of model (0.5%Pt/Sibunit) as well as industrial (0.5%Pt/Graphite) catalysts for hydroxylamine sulfate synthesis by NO hydrogenation in H2SO4 solution have been disclosed. It is shown that functionalization of the support surface with nitrogen-containing groups in the course of platinum deposition promotes not only metal dispersion but also a significant increase in its selectivity towards hydroxylamine sulfate. Based on experimental data, it is suggested that the maximal selectivity is inherent in the active centers representing single atoms or small clustersof platinum bound to nitrogen-containing ligands at the carbon surface.