WO3/g-C3N4异质结催化剂的制备及其氧化脱硫性能

以尿素和钨酸铵为原料采用浸渍法制备了金属氧化物三氧化钨（WO₃）与石墨相氮化碳（g-C₃N₄）异质结复合材料WO₃/g-C₃N₄。采用XRD、UV-vis、SEM、PL和XPS表征手段考察了催化剂的理化性质，发现WO₃与g-C₃N₄存在较好的相互作用和电子转移，保证了WO₃/g-C₃N₄本身所具有较高的氧化脱硫活性。以WO₃/g-C₃N₄作为催化剂，过氧化氢异丙苯为氧化剂，考察其光催化氧化脱硫性能，在反应温度80℃，O/S物质的量比为3.0的反应条件下，反应180 min，二苯并噻吩（DBT）转化率可以达到72.79%。通过游离基捕获实验，发现超氧自由基（·O₂^-）、电子（e^-）、羟基自由基（·OH）起到了促进反应速率的作用，并对该体系的反应机理进行了探讨。

Preparation of WO3/g-C3N4 heterojunction catalyst and its oxidative desulfurization performance

Graphite phase carbon nitride (g-C₃N₄) and metal oxide tungsten trioxide (WO₃) heterojunction nanocomposites WO₃/g-C₃N₄ were prepared by roasting from urea and ammonium tungstate. The physical and chemical properties of the catalysts were investigated by means of XRD, UV-vis, SEM, PL and XPS. The characterization indicated that WO₃ and g-C₃N₄ interacted well in the catalysts, and electron transfer occurred between them, which ensured high oxidative desulfurization activity of WO₃/g-C₃N₄. Supported catalyst WO₃/g-C₃N₄ was prepared using WO₃ as the support. Isopropyl peroxide was used as the oxidant to investigate the catalyst performance in oxidative desulfurization of the simulated oil. Under the reaction conditions of 80℃ and the content ratio of O/S at 3, a 72.79% of dibenzothiophene (DBT) conversion could be achieved after 180 min. It was fund that the superoxide free radicals (·O₂^-), electron (e^-) and hydroxyl free radicals (·OH) promoted the reaction rate through free radical capture experiment and the reaction mechanism was proposed.