Improving the catalytic efficiency of earth-abundant metals, such as nickel, through surface design has the potential to replace noble-metal-based catalysts. Here, we report that coating nickel with nitrogen-doped carbon (Ni@NC) enhances its stability and activity for the semi-hydrogenation of phenylacetylene under mild conditions. Mechanistic studies with substituted phenylacetylenes revealed an electronic effect that suggests a contribution of the homolytic cleavage of H₂ followed by hydrogen spillover to the N-doped carbon coating. As a result, the hydrogenation reaction occurs at temperatures as low as 25 °C, while the benchmark RANEY® nickel is inactive. These results are supported by a combination of experimental results and theoretical insights. Moreover, this efficient hydrogenation catalyst is resistant to carbon monoxide poisoning and remains active even at low temperatures.