**3. Catalyst activity test**

The catalytic activity and selectivity during the hydrogenation reactions were measured in a batch, PTFE-coated, stainless steel, stirred tank reactor, using pelletized or powder catalysts. The procedure used for starting the reaction comprised of the following steps. The reactor was charged with a solution of the substrate (styrene, 1-heptyne, 3-hexyne, 2,3-butanodione, ethyl pyruvate). The stirring rate used in each catalytic test was 1200 rpm. Pressure, temperature, and catalyst concentration values were different for each system.
