The exponential increase in CO₂ emission enforced the discovery of alternative methods to curb excessive atmospheric CO₂. In the present manuscript, nano-crystalline copper disperced TiO₂ (CuOx-TiO₂) catalyst has been explored for the direct hydrogenation of CO₂ into formic acid (FA) under hydrothermal condition. Series of Cu based catalysts were synthesized via a simple co-precipitation method and tested for CO₂ hydrogenation. Of the tested catalyst, CuOx-TiO₂ showed the highest TON (turnover number) 6.62 for FA under non-stringent reaction conditions (40 bar, 200 °C). The addition of base (both organic/ inorganic) showed significant improvement in CO₂ reduction. Inorganic bases showed a profound effect to obtain a higher yield of FA as compared to organic bases. The process intensification study was conducted for the influence of temperature, base, concentration of base, pressure, catalyst loading, and reaction time on FA production. The physicochemical properties of the synthesized catalyst were studied by using XRD, ATR-FTIR, BET, FEG-SEM, EDX, and ICP-OES analysis. Catalyst recyclability study showed the gradual drop in TON and TOF for five cycles but the easy regeneration process reboots the catalytic activity. The plausible reaction mechanism for direct hydrogenation of CO₂ to FA has also been proposed.

CO ₂排放的指数增长迫使人们发现了抑制大气中过量CO ₂的替代方法。在本文中，已经研究了纳米晶铜分散的TiO ₂（CuOx-TiO ₂）催化剂，用于在水热条件下将CO ₂直接加氢成甲酸（FA）。通过简单的共沉淀法合成了一系列的基于铜的催化剂，并测试了CO _2的氢化作用。在测试的催化剂中，CuOx-TiO ₂在非严格反应条件下（40 bar，200°C），FA的最高TON（周转数）为6.62。碱（有机/无机）的添加均显示了CO _2的显着改善减少。与有机碱相比，无机碱显示出更高的FA收率。进行了工艺强化研究，研究温度，碱，碱浓度，压力，催化剂负载和反应时间对FA生产的影响。通过XRD，ATR-FTIR，BET，FEG-SEM，EDX和ICP-OES分析研究了合成催化剂的理化性质。催化剂的可回收性研究表明，TON和TOF在五个循环中逐渐下降，但是易于再生的过程重新启动了催化活性。还提出了将CO ₂直接氢化为FA的合理的反应机理。