With the aim to meet ever-increasing strict regulations for three major exhaust gas pollutants, three-way catalytic technology has been effectively applied in automobile industries for purifying automobile exhaust gases. Here we report the efficiency of composite oxide Co₃O₄/TiO₂ with the addition of CeO₂ as a promotor. Modification of Co₃O₄/TiO₂ (15 wt%. Co/TiO₂) based composite catalyst synthesized by incipient wetness impregnation (IWI) method was followed by doping of ceria (CeO₂). The series of catalysts assigned as 15% IWI, 03-CE-IWI, 06-CE-IWI, and 09-CE-IWI having cerium content from 0 to 9 wt%, respectively were prepared. The same relative Co₃O₄/TiO₂ ratio i.e., 15 wt% was sustained in the CeO₂-doped catalysts for clarifying the impact of CeO₂ and its doping quantity for CO and HC oxidation along with NOx reduction. The catalysts were characterized by Scanning Electron microscopy (SEM), X-ray Diffraction (XRD), and Brunauer–Emmett–Teller (BET). The catalysts three-way catalytic converter efficiency was assessed, mounted on a motorcycle engine with an engine capacity of 70 cm³ spark ignition. It was evaluated under steady-state operational conditions. The results revealed the strong impact of doping of CeO₂ on Co₃O₄/TiO₂ composite under real engine operating conditions and the maximum doping, i.e., 09-CE-IWI can considerably enhance the surface area (41.5 m²/g). The improved performance can be credited to a higher dispersion of Co₃O₄/TiO₂ due to CeO₂ doping, possessing a higher surface area as compared to ceria undoped catalysts, and there exists a catalytic synergistic effect of Co₃O₄ and CeO₂. The 09-CE-IWI revealed the best catalytic activity for all three constituents i.e., CO and unburned HC at 6000 rpm and NOx specifically at 2000 rpm. Maximum three-way catalytic conversion efficiencies achieved in the case of CO, HC, and NOx are 92%, 83%, and 90%, respectively.

为了满足对三大尾气污染物日益严格的规定，三元催化技术已有效地应用于汽车行业净化汽车尾气。在这里，我们报告了添加 CeO ₂作为促进剂的复合氧化物 Co ₃ O ₄ /TiO ₂的效率。Co ₃ O ₄ /TiO ₂ (15 wt%. Co/TiO ₂ )基复合催化剂的改性，通过初湿浸渍(IWI)法合成，然后掺杂二氧化铈(CeO ₂）。分别制备了指定为15% IWI、03-CE-IWI、06-CE-IWI和09-CE-IWI的系列催化剂，其铈含量为0至9wt%。相同的相对 Co ₃ O ₄ /TiO ₂比率，即 15 wt% 在 CeO ₂掺杂的催化剂中保持不变，以阐明 CeO ₂及其掺杂量对 CO 和 HC 氧化以及 NOx 还原的影响。通过扫描电子显微镜 (SEM)、X 射线衍射 (XRD) 和 Brunauer-Emmett-Teller (BET) 对催化剂进行表征。评估了催化剂三元催化转化器的效率，安装在发动机容量为 70 cm ³的摩托车发动机上火花点火。它是在稳态操作条件下进行评估的。结果表明，在实际发动机工作条件下，CeO ₂掺杂对 Co ₃ O ₄ /TiO ₂复合材料的影响很大，并且最大掺杂，即 09-CE-IWI 可以显着提高表面积（41.5 m ² /g） . 改进的性能可以归功于由于 CeO ₂掺杂导致Co ₃ O ₄ /TiO ₂的更高分散，与未掺杂氧化铈的催化剂相比具有更高的表面积，并且存在 Co ₃ O ₄和 CeO的催化协同效应₂. 09-CE-IWI 显示了所有三种成分的最佳催化活性，即 CO 和未燃烧的 HC 在 6000 rpm 和 NOx，特别是在 2000 rpm。在 CO、HC 和 NOx 的情况下实现的最大三元催化转化效率分别为 92%、83% 和 90%。