Photocatalytic CO₂ reduction represents a sustainable route to generate syngas (the mixture of CO and H₂), which is a key feedstock to produce liquid fuels in industry. Yet this reaction typically suffers from two limitations: unsuitable CO/H₂ ratio and serious charge recombination. This paper describes the production of syngas from photocatalytic CO₂ reduction with a tunable CO/H₂ ratio via adjustment of the components and surface structure of CuPt alloys and construction of a TiO₂ mesoporous hollow sphere with spatially separated cocatalysts to promote charge separation. Unlike previously reported cocatalyst-separated hollow structures, we firstly create a reductive outer surface that is suitable for the CO₂ reduction reaction. A high evolution rate of 84.2 μmol h⁻¹ g⁻¹ for CO and a desirable CO/H₂ ratio of 1 : 2 are achieved. The overall solar energy conversion yield is 0.108%, which is higher than those of traditional oxide and sulfide based catalysts (generally about 0.006–0.042%). Finally, density functional theory calculations and kinetic experiments by replacing H₂O with D₂O reveal that the enhanced activity is mainly determined by the reduction energy of CO* and can be affected by the stability of COOH*.

中文翻译：

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由空间分离的助催化剂驱动的 光催化还原CO ₂和减少电荷重组而产生的可调谐合成气†

光催化还原CO ₂是产生合成气（CO和H ₂的混合物）的可持续途径，合成气是生产工业液体燃料的关键原料。然而，该反应通常遭受两个限制：不合适的CO / H ₂比和严重的电荷复合。本文介绍了通过调整CuPt合金的成分和表面结构以及TiO _2的结构，以可调节的CO / H ₂比，通过光催化还原CO _2来生产合成气的方法。介孔空心球，在空间上分离助催化剂以促进电荷分离。与以前报道的助催化剂分离的空心结构不同，我们首先创建一个适合于CO ₂还原反应的还原性外表面。对于CO而言，达到了84.2μmolh ^-1 g ^-1的高析出速率，并且CO / H ₂的理想比率为1：2。总体太阳能转化率为0.108％，高于传统的基于氧化物和硫化物的催化剂（通常约为0.006-0.042％）。最后，通过用D ₂代替H ₂ O进行密度泛函理论计算和动力学实验O表明增强的活性主要由CO *的还原能决定，并且可以受COOH *的稳定性影响。