TY - JOUR

T1 - Porous nanocrystalline silicon supported bimetallic Pd-Au catalysts

T2 - Preparation, characterization, and direct hydrogen peroxide synthesis

AU - Potemkin, Dmitriy I.

AU - Maslov, Dmitry K.

AU - Loponov, Konstantin

AU - Snytnikov, Pavel V.

AU - Shubin, Yuri V.

AU - Plyusnin, Pavel E.

AU - Svintsitskiy, Dmitry A.

AU - Sobyanin, Vladimir A.

AU - Lapkin, Alexei A.

N1 - Publisher Copyright: © 2018 Potemkin, Maslov, Loponov, Snytnikov, Shubin, Plyusnin, Svintsitskiy, Sobyanin and Lapkin.

PY - 2018/3/27

Y1 - 2018/3/27

N2 - 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 characterized 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 (DCS) 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 mol gPd-1 h-1 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 H2O2 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.

AB - 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 characterized 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 (DCS) 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 mol gPd-1 h-1 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 H2O2 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.

KW - Alloy nanoparticles

KW - Bimetallic nanoparticles

KW - Direct HO synthesis

KW - Direct hydrogen peroxide synthesis

KW - Double complex salts

KW - Gold-palladium catalysts

KW - Pd-Au catalysts

KW - Porous silicon

KW - porous silicon

KW - PERFORMANCE

KW - H2O2

KW - direct hydrogen peroxide synthesis

KW - double complex salts

KW - NANOCOMPOSITES

KW - MILD CONDITIONS

KW - bimetallic nanoparticles

KW - direct H2O2 synthesis

KW - ACTIVE-SITES

KW - DECOMPOSITION

KW - gold-palladium catalysts

KW - HETEROGENEOUS CATALYSIS

KW - PREFERENTIAL CO OXIDATION

KW - OXYGEN

KW - NANOPARTICLES

KW - alloy nanoparticles

UR - http://www.scopus.com/inward/record.url?scp=85047448289&partnerID=8YFLogxK

U2 - 10.3389/fchem.2018.00085

DO - 10.3389/fchem.2018.00085

M3 - Article

C2 - 29637068

AN - SCOPUS:85047448289

VL - 6

SP - 85

JO - Frontiers in Chemistry

JF - Frontiers in Chemistry

SN - 2296-2646

IS - MAR

M1 - 85

ER -