The burning of fossil fuels contributes to the emission of CO2 in the environment and CH4 is emitted from different natural sources such as wetlands and from different organic and industrial wastes. Capturing both of these gases has been a major challenge. Basically, three approaches can be undertaken in order to reduce the global greenhouse gas concentrations: (a) decreasing emission, (b) carbon capture and storage (CCS) and (c) chemical conversion into alternative useful fuels. Solid adsorbents can be used to achieve a cost-effective and low-carbon foreseeable future. But the current sequestration of CO2 has several technical limitations that include safety concerns and leakage issues. So, a long-term alternative solution of CO2 mitigation is the sustainable conversion of CO2 gas into value-added fuels by using heterogeneous catalysis techniques utilizing renewable energy as input electric energy. In this first part of the work, a variety of solid adsorbents have been studied comprehensively for CO2 capture and CH4 storage. A high gas uptake is normally correlated with a high pore volume and surface area. Besides, different structural parameters have also been seen to affect the gas adsorption properties of these particular nanocomposites. In the second part of the work, the design of a full electrochemical cell based on conventional PEMFC configuration is reported to demonstrate electrochemical CO2 conversion at room temperature and ambient pressure using different non-platinum based cost-effective electrocatalysts.