Unimolecular decomposition of NH3 on tungsten surface is inhibited by one of the products, H2. The rate of surface catalyzed decomposition is given by
Pi and Ki are, respectively, the partial pressure and surface binding constant of the ith species; kc is the rate constant of rate determining step
1
\(\frac{k_c K_{N H_3} P_{N H_3} K_{H_2} P_{H_2}}{\left(1+K_{N H_3} P_{N H_3} K_{H_2} P_{H_2}\right)^2}\)
2
\(\frac{k_c K_{N H_3} P_{N H_3}}{1+K_{N H_3} P_{N H_3}}\)
3
\(\frac{k_c K_{N H_3} P_{N H_3}}{1+K_{N H_3} P_{N H_3}+K_{H_2} P_{H_2}}\)
4
\(\frac{k_c K_{\mathrm{NH}_3} P_{N H_3} K_{H_2} P_{H_2}}{1+K_{N H_3} P_{N H_3}+K_{H_2} P_{H_2}}\)