Hydrogenation and hydrogenolysis reaction and solvent effect on catalytic reactions have been carried out traditionally in batch reactors under high temperature , and pressure conditions in the presence of hydrogen gas fed into the reactor from an external source. Recently, electrochemical hydrogenation and hydrogenolysis has attracted a lot of attention since reactions can be carried in mild conditions (room temperature and ambient pressure) in the presence of water as an external hydrogen source. Electrocatalysis can be combined with renewable energy resources (i.e.e.g. biomass and solar cells) to yield a sustainable path to producing valuable chemicals that can be used as solvents and/or biofuel from biomass feedstock. An additional advantage of electrocatalysis is the added degree of freedom (i.e. electrode potential) that can be controlled to tune reaction pathways. This thesis highlights the role of solvents and charge transfer in accelerating the rate of hydrogenation of oxygenates and improves selectivity in both thermal- and electro-catalytic reactions through a combination of experimental and computational techniques (DFT).