Potemkin Dmitriy I, Maslov Dmitry K, Loponov Konstantin, Snytnikov Pavel V, Shubin Yuri V, Plyusnin Pavel E, Svintsitskiy Dmitry A, Sobyanin Vladimir A, Lapkin Alexei A
Laboratory of the Energy-Efficient Catalytic Processes, Novosibirsk State University, Novosibirsk, Russia.
Department of Heterogeneous Catalysis, Boreskov Institute of Catalysis, Novosibirsk, Russia.
Front Chem. 2018 Mar 27;6:85. doi: 10.3389/fchem.2018.00085. eCollection 2018.
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 H[PdCl] and H[AuCl] precursors contains monometallic Pd and a range of different Pd-Au alloy nanoparticles over the oxidized PSi surface. The PdAu/PSi catalyst prepared from the [Pd(NH)][AuCl] 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 Pd and Pd states. Among the catalysts studied, the PdAu/PSi catalyst was the most active and selective in the direct HO synthesis with HO productivity of 0.5 [Formula: see text] at selectivity of 50% and HO concentration of 0.023 M in 0.03 M HSO-methanol solution after 5 h on stream at -10°C and atmospheric pressure. This performance is due to high activity in the HO synthesis reaction and low activities in the undesirable HO decomposition and hydrogenation reactions. Good performance of the PdAu/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.
首次在多孔纳米晶硅（PSi）上制备了双金属Pd-Au催化剂。对这些催化剂进行了过氧化氢直接合成反应测试，并采用标准的结构和化学技术对其进行了表征。结果表明，由传统的H[PdCl]和H[AuCl]前驱体制备的Pd-Au/PSi催化剂在氧化的PSi表面含有单金属Pd和一系列不同的Pd-Au合金纳米颗粒。由[Pd(NH)][AuCl]双络合盐（DCS）单源前体制备的PdAu/PSi催化剂主要含有双金属Pd-Au合金纳米颗粒。对于这两种催化剂，双金属纳米颗粒的表面富含Pd，且含有Pd和Pd状态的钯。在所研究的催化剂中，PdAu/PSi催化剂在过氧化氢直接合成中活性和选择性最高，在-10°C和常压下反应5小时后，在0.03 M HSO-甲醇溶液中，HO生产率为0.5 [公式：见原文]，选择性为50%，HO浓度为0.023 M。这种性能归因于在HO合成反应中的高活性以及在不需要的HO分解和氢化反应中的低活性。PdAu/PSi催化剂的良好性能与催化剂中大部分Pd以双金属Pd-Au纳米颗粒的形式存在有关。由于多孔硅对不需要的副反应具有惰性、高热稳定性和导电性、在高温高压下安全操作的可能性以及成熟的制造工艺，因此得出结论，多孔硅是过氧化氢直接合成的一种有前途的催化载体。
