A multi-component two-phase lattice Boltzmann method of the Shan-Chen type has been developed for simulating the complex interplay of diffusion and surface reaction in a multi-component gas-liquid catalytic chemical reactor. This method development comprised of various steps, viz, the formulation, implementation, and validation of lattice Boltzmann techniques capable of reproducing, among other things, species transport across a phase interface, a chemical reaction at a catalytic surface, and a phase change due to the surface reaction, which all are relevant to the Fischer-Tropsch Synthesis (FTS). The most important steps taken in developing method and implementation, along with some validations are discussed. This paper presents the results of the simulations for a simplified isothermal 1-D FTS case with a liquid film covering a catalytic surface and gradually growing due to the surface reaction. (C) 2012 Elsevier B.V. All rights reserved.