Original Research ARTICLE
Porous nanocrystalline silicon supported bimetallic Pd-Au catalysts: preparation, characterization and direct hydrogen peroxide synthesis
- 1Novosibirsk State University, Russia
- 2Boreskov Institute of Catalysis (RAS), Russia
- 3Department of Chemical Engineering and Biotechnology, University of Cambridge, United Kingdom
- 4Nikolaev Institute of Inorganic Chemistry (RAS), Russia
- 5Cambridge Centre for Advanced Research and Education in Singapore Ltd, Singapore
Bimetallic Pd-Au catalysts were prepared on the porous nanocrystalline silicon (PSi) for the first time. The catalysts were tested in the reaction of direct hydrogen peroxide synthesis and characterised by standard structural and chemical techniques. It was shown that the Pd-Au/PSi catalyst prepared from conventional H2[PdCl4] and H[AuCl4] precursors contains monometallic Pd and a range of different Pd-Au alloy nanoparticles over the oxidized PSi surface. The PdAu2/PSi catalyst prepared from the [Pd(NH3)4][AuCl4]2 double complex salt single-source precursor predominantly contains bimetallic Pd-Au alloy nanoparticles. For both catalysts the surface of bimetallic nanoparticles is Pd-enriched and contains palladium in Pd0 and Pd2+ states. Among the catalysts studied, the PdAu2/PSi catalyst was the most active and selective in the direct H2O2 synthesis with H2O2 productivity of 0.5 at selectivity of 50 % and H2O2 concentration of 0.023 M in 0.03 M H2SO4-methanol solution after 5 h on stream at -10 °C and atmospheric pressure. This performance is due to high activity in the H2O2 synthesis reaction and low activities in the undesirable Н2О2 decomposition and hydrogenation reactions. Good performance of the PdAu2/PSi catalyst was associated with the major part of Pd in the catalyst being in the form of the bimetallic Pd-Au nanoparticles. Porous silicon was concluded to be a promising catalytic support for direct hydrogen peroxide synthesis due to its inertness with respect to undesirable side reactions, high thermal stability and conductivity, possibility of safe operation at high temperatures and pressures and a well-established manufacturing process.
Keywords: Direct H2O2 synthesis, Direct hydrogen peroxide synthesis, porous silicon, bimetallic nanoparticles, Alloy nanoparticles, Pd-Au catalysts, gold-palladium catalysts, double complex salts, Single-source precursor
Received: 30 Jan 2018;
Accepted: 12 Mar 2018.
Edited by:Heqing Jiang, Qingdao Institute of Bioenergy and Bioprocess Technology (CAS), China
Reviewed by:Mingxing Wu, Hebei Normai University, China
Yan Zhang, Qingdao Institute of Bioenergy and Bioprocess Technology (CAS), China
Copyright: © 2018 Potemkin, Maslov, Loponov, Snytnikov, Shubin, Plyusnin, Svintsitskiy, Sobyanin and Lapkin. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Prof. Alexei Lapkin, University of Cambridge, Department of Chemical Engineering and Biotechnology, Philippa Fawcet Drive, Cambridge, CB3 0AS, United Kingdom, email@example.com