In some examples, a composition includes a hydrocarbon and ozone catalyst. The hydrocarbon and ozone catalyst includes one or more catalytic layers overlying a substrate. The one or more catalytic layers include a non-catalytic component, an ozone catalytic component, and a hydrocarbon catalytic component. The non-catalytic component includes titanium oxide. The ozone catalytic component includes cobalt oxide. The hydrocarbon catalytic component includes platinum. An outermost layer of the one or more catalytic layers includes the hydrocarbon catalytic component distributed in the non-catalytic component.