Mitigation of CO₂ emissions has become an important issue nowadays, as well as its reutilization as a carbon source to obtain chemicals and fuels. CO₂ conversion to CH₄ comes up as an interesting alternative, since it is a natural gas substitute and H₂ storage source. In this study, Ni/SiO₂ catalysts promoted by Fe, Co and Zn were prepared by simple wet impregnation and evaluated in the CO₂ conversion to methane. The samples were characterized by TGA-DTA, XRD, N₂ physisorption, H₂-TPR and TPO-DTA. The reactions were carried out at 1 atm in a fixed bed reactor with H₂/CO₂ = 4 and online GC analysis. The addition of a second metal enhanced the surface area and lowered the Ni° crystallite size, indicating that metallic dispersion was improved. These characteristics had positive influence on the methanation performance of the Fe and Co promoted catalysts, which showed improved CO₂ conversion and CH₄ selectivity in comparison to unpromoted catalysts. Ni-Co/SiO₂ presented the best results, attaining 73 % of CO₂ conversion and 98.5 % of CH₄ selectivity at 350 °C and high resistance to sintering. The catalyst promoted by Fe presented the higher resistance to carbon formation, whereas the promotion with Zn led to a strong decrease in selectivity for CH₄ and a consequent increase in selectivity for CO. These results suggest the use of both Fe and Co as promoters of Ni/SiO₂ catalysts has a high potential for the CO₂ conversion to CH₄.

如今，减少CO ₂排放以及将其重新用作获取化学品和燃料的碳源已成为一个重要问题。将CO ₂转化为CH ₄是一种有趣的选择，因为它是天然气的替代品和H _2的储存源。在这项研究中，通过简单的湿法浸渍制备了由Fe，Co和Zn促进的Ni / SiO ₂催化剂，并评估了将CO ₂转化为甲烷的能力。通过TGA-DTA，XRD，N ₂物理吸附，H ₂ -TPR和TPO-DTA表征样品。反应在具有H ₂ / CO _2的固定床反应器中在1 atm进行。= 4和在线GC分析。添加第二种金属可增加表面积并降低Ni°微晶尺寸，表明金属分散性得到改善。这些特性对Fe和Co助催化剂的甲烷化性能具有积极影响，与未助催化剂相比，这些催化剂的CO ₂转化率和CH ₄选择性提高。Ni-Co / SiO ₂表现最好，在350°C时可获得73％的CO ₂转化率和98.5％的CH ₄选择性，并且具有很高的抗烧结性。Fe促进的催化剂表现出更高的抗碳形成能力，而Zn促进导致对CH _4的选择性大大降低。这些结果表明，同时使用Fe和Co作为Ni / SiO ₂催化剂的促进剂，具有将CO ₂转化为CH ₄的高潜力。