The direct epoxidation of propylene to propylene oxide (PO) represents a unique feature of gold nanoparticle catalysts. Different amounts of vanadium were introduced into TS-1 using a hydrothermal method to give V-TS-1, and the effect of various vanadium loadings on the catalytic performance of Au/V-TS-1 was investigated in the epoxidation of propylene under different reaction conditions. The obtained characterization results indicate that the molecular sieve pore structure and crystalline phase structure of TS-1 were maintained after vanadium incorporation, and vanadium was incorporated into the molecular sieve framework. The introduction of an appropriate amount of vanadium resulted in the homogeneous dispersion of gold particles with a small average particle size, which facilitated the epoxidation reaction. When V was introduced into TS-1, the propylene conversion decreased under the condition of 10 % H2 concentration (C3H6/H2 = 1/1) in the reaction atmosphere, but the PO selectivity was maintained. Interestingly, when the H2 concentration in the reaction atmosphere was lowered to 2 % (C3H6/H2 = 3/1), the propylene conversion in Au/TS-1 was significantly decreased compared to 10 % H2 concentration condition, while in Au/V-TS-1, the propylene conversion was maintained in 2 % H2 concentration condition compared to 10 % H2. Au/V-TS-1 also maintained its selectivity for PO even when the H2 concentration was lowered. Therefore, under low hydrogen concentration conditions, the PO formation rate of Au/V-TS-1 was much higher than that of Au/TS-1. More, the same trend was observed when Mo was added in place of V. Our strategy will guide the design of future catalysts as a way to utilize hydrogen more effectively while maintaining PO productivity.

中文翻译：

---

在掺杂 V 的 TS-1 负载的 Au 纳米颗粒上进行丙烯环氧化反应时，低氢浓度下有效形成环氧丙烷


丙烯直接环氧化为环氧丙烷（PO）代表了金纳米粒子催化剂的独特特征。采用水热法在TS-1中引入不同量的钒得到V-TS-1，并考察了不同钒负载量对Au/V-TS-1在不同条件下丙烯环氧化反应中催化性能的影响。反应条件。得到的表征结果表明，掺钒后TS-1的分子筛孔结构和晶相结构得以保持，钒被纳入分子筛骨架中。适量钒的引入使金颗粒均匀分散，平均粒径较小，有利于环氧化反应。当TS-1中引入V时，在反应气氛中H2浓度为10％(C3H6/H2=1/1)的条件下，丙烯转化率下降，但PO选择性得以保持。有趣的是，当反应气氛中的H2浓度降低至2％（C3H6/H2 = 3/1）时，与10％H2浓度条件相比，Au/TS-1中的丙烯转化率显着下降，而在Au/V中-TS-1，与 10% H2 相比，在 2% H2 浓度条件下丙烯转化率保持不变。即使 H2 浓度降低，Au/V-TS-1 也能保持对 PO 的选择性。因此，在低氢浓度条件下，Au/V-TS-1的PO形成速率远高于Au/TS-1。此外，当添加 Mo 代替 V 时，也观察到了相同的趋势。我们的策略将指导未来催化剂的设计，以更有效地利用氢气，同时保持 PO 生产率。