Pd/WO₃复合材料的制备及其光催化CO₂耦合CH₃OH制备DMC性能研究

Preparation of Pd/WO₃ Composite and Its Photocatalytic Properties for Preparation of DMC by CO₂ Coupled with CH₃OH

摘要: 本论文采用水热法，以钨酸钠制备了六方相三氧化钨纳米半导体材料。采用硼氢化钠还原方法将贵金属Pd以不同比例负载到WO₃催化剂上，分别制备出0.5% Pd/WO₃、1% Pd/WO₃、1.5% Pd/WO₃复合材料。通过XRD和SEM对其结构和形貌进行了表征。以CH₃OH耦合CO₂制备碳酸二甲酯(DMC)为探针反应，探究其光催化性能。研究表明，成功制备得的WO₃半导体材料，经过Pd金属复合的光催化剂表现出更高的光催化CO₂转化活性，负载Pd金属的WO₃的光催化性能显著高于纯WO₃。其中，0.5% Pd/WO₃的DMC产率最高，为3.52 μg.g⁻¹，是WO₃样品的5.6倍。DRS和电化学测试结果表明提高的性能来源于Pd/WO₃更高的光吸收性能和光电响应强度。

Abstract: In this paper, hexagonal tungsten trioxide semiconductor materials were prepared by hydrothermal method with sodium tungstate as the precursor. The precious metal Pd was loaded onto WO₃ via the sodium borohydride reduction method. The 0.5% Pd/WO₃, 1% Pd/WO₃, 1.5% Pd/WO₃ composites were synthesized. The structure and morphology of the obtained samples were characterized by XRD and SEM. The photocatalytic activity of the as prepared samples were evaluated by CO₂ coupled with CH₃OH into dimethyl carbonate (DMC). The results showed that the loading of Pd onto WO₃ can significantly improve the photocatalytic performance. 0.5% Pd/WO₃ show the highest DMC yield of 3.52 μg.g⁻¹, which was 5.6 times higher than that of WO₃ sample. The results of DRS and electrochemical measurements suggested that the improved performance originated from the higher light absorption performance and photoelectric response intensity of Pd/WO₃.