The present invention is directed to an improved hydrocarbon adsorbent slurry washcoat formulation, which can be used for controlling evaporative hydrocarbon emissions from a motor vehicle. More specifically, the present invention is directed to an improved slurry composition of the present invention comprises one or more hydrocarbon adsorbent materials, and an organic polymer binder containing an anionic dispersant and/or stabilizing pH. The binder is used to improve the adhesion of the hydrocarbon adsorbent to the surface of the fuel storage, fuel delivery, or air intake system component.