Hi Iris,

The hydrogenation of CO2 to methane (CO2 methanation) occurs in the gas phase at around 300 °C using solid catalysts, usually based on Ni. To be homogeneous, the catalyst should be a gas (or liquid), which is hardly feasible.

You are probably looking in the wrong places. Information on CO2 methanation is available on the RG. It concerns the technology of the process, its kinetics and thermodynamics.

Hi Iris Sancho

I agree with Oscar W. Perez-Lopez answer since CO2 is an inert molecule in certain conditions which can be adopted for homogeneous catalysis. Even though it is a little acidic if you want to activate which needs more energy like high temperature and pressure. Hence you found many articles on heterogeneous over the homo. On the contrary, some of the successful homogeneous catalytic processes also available in the litrature, for example,

https://link.springer.com/article/10.1007/s41061-017-0107-x#:~:text=Catalytic%20hydrogenation%20of%20CO2,and%20methane%20(CH4).

https://pubs.rsc.org/en/content/articlelanding/2014/cy/c3cy00564j#!divCitation

https://www.google.com/search?q=homogeneous+hydrogenation+of+CO2+to+methane&rlz=1C1JZAP_enIN944IN944&oq=homogeneous+hydrogenation+of+CO2+to+methane&aqs=chrome..69i57j69i60l2&sourceid=chrome&ie=UTF-8