Hydrophobic Cr–Si mixed oxides as a catalyst for visible light-induced partial oxidation of cyclohexane
Hydrophobic Cr–Si mixed oxides as a catalyst for visible light-induced partial oxidation of cyclohexane
复制标题
DOI：
10.1039/c0nj00423e
复制
发表时间：
2010-11
影响因子：
3.3
通讯作者：
Yasuhiro Shiraishi;H. Ohara;T. Hirai
中科院分区：
文献类型：
--
作者：
Yasuhiro Shiraishi;H. Ohara;T. Hirai
以疏水Cr-Si混合氧化物为催化剂，在可见光（λ > 400 nm）照射下进行了环己烷（CHA）与分子氧的光催化氧化。以正硅酸四乙酯（TEOS）、有机烷氧基硅烷（1,2-二（三乙氧基硅基）乙烷：BTESE）和Cr(NO3)3为水解原料，煅烧制备了铬酸盐高度分散的Cr - si催化剂。Cr-Si催化剂均促进CHA部分氧化生成环己醇（CHA-ol）和环己酮（CHA-one），选择性高（约99%）。在不同TEOS和BTESE组成的Cr-Si催化剂中，10% BTESE组成的催化剂表现出最高的催化活性。CHA蒸气吸附和电子自旋共振分析表明，催化活性的增强是由于催化剂表面疏水性的增强，从而促进了CHA与激发态铬酸盐的接触。
Photocatalytic oxidation of cyclohexane (CHA) with molecular oxygen has been performed with hydrophobic Cr–Si mixed oxides as a catalyst under visible light irradiation (λ > 400 nm). The Cr–Si catalysts with highly dispersed chromate species were prepared by hydrolysis of tetraethyl orthosilicate (TEOS), organoalkoxysilane (1,2-bis(triethoxysilyl)ethane: BTESE), and Cr(NO3)3 followed by calcination. All of the Cr–Si catalysts promote partial oxidation of CHA to cyclohexanol (CHA-ol) and cyclohexanone (CHA-one) with high selectivity (>99%). Among the Cr–Si catalysts prepared with different TEOS and BTESE compositions, the catalyst prepared with 10% BTESE demonstrates the highest catalytic activity. The CHA vapor adsorption and electron spin resonance analysis reveal that the enhanced catalytic activity is due to the increased hydrophobicity of the catalyst surface, which enhances the access of CHA to the excited state chromate species.