【摘要】 本文对比研究了Keggin结构的Cs_2.9Cu_0.34V_0.49PMo₁₂O₄₀多酸热催化和光热催化异丁烷选择氧化制备甲基丙烯酸反应.光的引入同时增加了异丁烷转化率和甲基丙烯酸选择性,从而显著提高了甲基丙烯酸收率.光的促进效应在较低反应温度下尤为显著.表征结果表明,催化剂表面甲基丙烯醛氧化生成甲基丙烯酸反应是异丁烷选择氧化生成甲基丙烯酸反应的速控步,而光照促进了催化剂表面吸附的甲基丙烯醛与表面羟基反应生成甲基丙烯酸.研究结果表明了热催化和光催化在异丁烷选择氧化制备甲基丙烯酸反应中的协同效应.因此,光热催化是温和条件下实现烷烃选择氧化反应的可行途径.更多还原

【Abstract】 Thermal and photothermal catalytic selective oxidation of isobutane to methacrylic acid（MAA） are comparatively studied over a keggin-type Cs_2.9Cu_0.34V_0.49PMo₁₂O₄₀ heteropolyacid acid.An introduction of light was observed to enhance both the i-C₄H₁₀conversion and the MAA selectivity,and consequently the MAA formate rate,particularly at low temperatures.Characterization results show that oxidation of methacrolein（MAL） to MAA is the rate-limiting step while UV light illumination promotes the oxidation of σ-bonded MAL with OH groups to σ-bonded MAA on the catalyst surface.These results demonstrate a synergistic effect of thermal catalysis and photocatalysis in selective oxidation of isobutane to MAA,which suggests photothermal catalysis as a promising strategy to catalyze the selective oxidation of higher hydrocarbons at relative mild reaction conditions.更多还原