Determination of the Surface Heterogeneity of Solid Particulates using the Patchwise Adsorption Model

Abstract

Two methods of solution of the integral equation describing the physical adsorption of gases on polysorptic surfaces have recently been developed. The derived algorithms, HILDA and CAEDMON, are compared in detail by applying them to the analysis of krypton adsorbed on silver iodide and nitrogen adsorbed on Spheron-6 (untreated and partially annealed), all measured near 77 K. The numerical results are presented in the form of adsorptive energy distributions. The differences between the results from the two programs, most evident in the case of nitrogen adsorbed on Spheron-6, are explained in terms of the convergence and accuracy of the two methods. The program HILDA is found to yield more detail about the heterogeneity distributions than CAEDMON and subsequently more information about the effects of annealing the Spheron-6 surface.