二氧化硫水溶液在修饰硫化镉粉末上的光催化反应

本文从应用意图出发,采用CdS、混Pt/CdS和镀Pt/CdS三种光催化剂,研究(1)反应温度,(2)催化剂表面含Pt量,(3)修饰方法和催化剂表面结构形貌对光催化SO₂水溶液生成H₂SO₄同时放H₂反应的活性和选择性的影响。结果表明:(1)本反应有明显温度效应,利用太阳能中约占50％的红外段辐射来提高反应温度到70℃可使活性增至7倍,但选择性下降,(2)估算了反应活化能为21kJ·mol^-1,(3)得出60℃为反应较佳温度,(4)表面含Pt量在5％左右活性最高,(5)混Pt/CdS体系形成高分散、细颗粒分布,其催化活性比镀Pt/CdS体系为高。根据实验结果对反应机理进行了一些讨论。

PHOTOCATALYTIC REACTION OF AQUEOUS SOLUTION OF SULFUR DIOXIDE ON MODIFIED CADMIUM SULFIDE POWDER

In the present paper, influence of (1) reaction temperature (2) pt content on catalyst by applying the IR surface and (3) modified procedure and surface structure of catalysts on pho-tocatalytic activity and selectivity of reaction in the presence of Cds, mixed Pt/CdS and plated Pt/CdS was investigated.Experimental results indicated that (1) a rise in reaction temperature by applying the IR irradiation of solar energy can increase the photocatalytic activity by seven times but decrease the selectivity, (2) the activation energy is 21 kJ mol^-2, (3) 60℃ seems to be the optimal reaction temperature, (4) photocatalyst with about 5% Pt content maximizes the catalytic activity, and (5) catalytic activity for mixed Pt/Cds catalyst is higher than that of plated Pt/CdS catalyst due to higher dispersity and more fine particle distribution. The reaction mechanism was discussed in some detail.