Coverage dependent desorption energy of molecular hydrogen induced by encounter desorption: the quantum tunneling effects

In previous studies, the effective desorption energy based on the encounter desorption (ED) mechanism successfully explained the coverage-dependent H2 desorption energy measured in experiments, . We introduce quantum tunneling effects and further study using the ED mechanism. The effective desorption energy can still successfully explain if quantum tunneling effects are considered. We find the impact of quantum tunneling is significant at 15 K if the barrier width is small (<2.0). Moreover, in order that the effective desorption energy agrees well with , hydrogen molecules should diffuse more slowly, or their desorption energy on the H2 substrate should be larger if the quantum tunneling is considered.