Efforts in the fields of materials science have allowed us to create smaller and smaller metal nanoparticles, creating new opportunities to study catalytic properties that depend on the metal particle size. Structure sensitivity is the phenomenon where not all surface atoms in a supported metal catalyst have the same activity. Understanding of structure sensitivity can assist in the rational design of heterogeneous catalysts allowing to control mechanisms, activity and selectivity. By making use of advanced characterization methods, we wish to investigate how structure sensitivity in supported Ni catalysts influences hydrogenation catalysis by taking CO2 reduction as a showcase. These findings may bring new understanding in selective reactant adsorption (e.g. H2, CO2 and olefins) and allow controlling both activity and selectivity hydrogenation catalysis over supported Ni catalysts, which can be a means for CO2 emission abatement.