US Patent 8133837 Exhaust gas-purifying catalyst

Decreasing HC emission is made possible. An exhaust gas-purifying catalyst includes a substrate, a hydrocarbon-adsorbing layer covering the substrate, and a catalytic layer covering the hydrocarbon-adsorbing layer. The catalytic layer includes a layered structure of a first catalytic layer including a precious metal and a carrier supporting it, and a second catalytic layer including the same precious metal as the precious metal of the first catalytic layer and a carrier supporting it and having a concentration of the precious metal higher than that in the first catalytic layer.