A Shaker Hydrogenator is a laboratory-scale reactor used for catalytic hydrogenation reactions. It consists of a pressure vessel that can hold a liquid substrate, catalyst, and hydrogen gas, while a mechanical shaking mechanism ensures proper mixing. It is a long-tested design and commonly used for smaller scale hydrogenations in research and development e.g. reducing double bonds, nitro groups, or aromatic rings. Due to its simplicity and efficiency, it is ideal for exploratory synthesis and testing catalytic activity in hydrogenation reactions.