Platinum was immobilized on magnetic silica gel by means of boronic, nitric, carboxylic or sulfuric acid ligands to give four heterogeneous Pt nano-catalysts, designated as Fe3O4@SiO2-BA@Pt, Fe3O4@SiO2-NA@Pt, Fe3O4@SiO2-CA@Pt and Fe3O4@SiO2-SA@Pt, respectively. Particles of these mono-dispersible Pt catalysts were 10–20 nm in size and could be separated for recycling by means of a magnet. Fe3O4@SiO2-BA@Pt (0.174 mmol/g Pt) showed the best catalytic activity and selectivity, which were better than Speier’s catalyst. Its turnover numbers were up to 1.7 × 106 and 1.1 × 106 for hydrosilylation of 1-hexene or styrene, respectively. This material could also catalyze the hydrosilylation of a broad range of alkenes and alkynes as substrates and methyldichlorosilane or triethoxysilane as silanes. Similar yields of 1-hexyl-methyldichlorosilane at the first and eighth runs (96.5% and 95.2%, respectively), together with a final Pt content of 0.171 mmol/g indicated the outstanding stability of Fe3O4@SiO2-BA@Pt under the catalytic reaction conditions.

中文翻译：

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一系列不同酸配体固定在磁性二氧化硅上的多相铂催化剂的制备、表征和评价

通过硼酸、硝酸、羧酸或硫酸配体将铂固定在磁性硅胶上，得到四种异质铂纳米催化剂，分别命名为 Fe3O4@SiO2-BA@Pt、Fe3O4@SiO2-NA@Pt、Fe3O4@SiO2-分别为 CA@Pt 和 Fe3O4@SiO2-SA@Pt。这些单分散 Pt 催化剂的颗粒大小为 10-20 nm，可以通过磁铁分离回收。Fe3O4@SiO2-BA@Pt (0.174 mmol/g Pt) 表现出最好的催化活性和选择性，优于 Speier 的催化剂。对于 1-己烯或苯乙烯的氢化硅烷化，其转换数分别高达 1.7 × 106 和 1.1 × 106。这种材料还可以催化广泛的烯烃和炔烃作为底物和甲基二氯硅烷或三乙氧基硅烷作为硅烷的氢化硅烷化。