Critical phenomena in a nonequilibrium model of heterogeneous catalysis

A simple irreversible kinetic model recently introduced by Ziff, Gulari, and Barshad [Phys. Rev. Lett. 56, 2553 (1986)] to describe the catalysis of chemical reactions on regular surfaces has been shown to have a second-order phase transition from an absorbing state, wherein the surface is passivated (rendered catalytically inactive or ‘‘poisoned’’) by one of the chemical constituents, to an active steady state. We argue here that this transition belongs in the universality class of Reggeon field theory, i.e., of directed percolation.