Ziff-Gulari-Barshad model with CO desorption: An Ising-like nonequilibrium critical point

The Ziff-Gulari-Barshad model for the reaction: CO+O→${\mathrm{CO}}_2$ on a catalytic surface exhibits a first-order transition to a CO-poisoned state, as the CO adsorption rate is varied. If the model is modified to include desorption of CO at rate k, the first-order transition line terminates at a critical point ${\mathit{k}}_{\mathit{c}}$. Here we present detailed simulations of the critical behavior. The results support theoretical arguments placing the transition in the Ising-model universality class.