Anatase TiO₂, a widely used semiconductor metal oxide support, was tested for biomimetic carbonic anhydrase activity catalyzing the reversible hydration of CO₂ to bicarbonate ions. Owing to superior photocatalytic response of nanoclusters of TiO₂ and its apparent role in catalyzing CO₂ hydration, (TiO₂)₁₅ nanocluster was tested for the reaction using density functional theory calculations. Free energy landscape of the reaction was developed following the biological mechanism consisting of H₂O adsorption, deprotonation, CO₂ complexation, CO₂ bending, intramolecular proton transfer, and bicarbonate ion displacement. The identity of the intermediates of the mechanistic cycle was further confirmed by computational nuclear magnetic resonance and infrared spectroscopic studies. A close correspondence of the computational and reported experimental spectroscopic analyses confirmed the identity of the intermediates and the presence of biomimesis over the TiO₂ cluster.

中文翻译：

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二氧化钛纳米团簇的仿生CO2水合活性的机理见解

测试了锐钛矿型TiO ₂（一种广泛使用的半导体金属氧化物载体）的仿生碳酸酐酶活性，该活性催化了CO ₂可逆水合为碳酸氢根离子。由于TiO ₂纳米团簇具有优异的光催化响应及其在催化CO ₂水合中的明显作用，因此使用密度泛函理论计算对（TiO ₂）₁₅纳米团簇进行了反应测试。根据H ₂ O吸附，去质子化，CO ₂络合，CO ₂的生物学机理，开发了反应的自由能态。弯曲，分子内质子转移和碳酸氢根离子置换。通过计算核磁共振和红外光谱研究进一步证实了机械循环中间体的身份。计算和报告的实验光谱分析的密切对应关系证实了中间体的身份和TiO ₂ 团簇上的生物模仿作用。