Absolute dissociation cross sections for D2 dissociation on Pt steps

Accurate Simulations of the Reaction of H2on a Curved Pt Crystal through Machine Learning

“… 53 In subsequent experimental work by Jansen and Juurlink, the step sticking cross section has been determined. 54 Interestingly, Jansen and Juurlink found that at a low incidence energy the step sticking cross section was dependent on the step density. The reason for this step density dependence was unknown, and it was suggested that theoretical dynamical studies are required to understand the dependence.…”

“…Figure 2 a compares the computed and measured 54 sticking probability of D 2 on stepped Pt surfaces as a function of step density. Throughout this work, theoretical results correspond to a specific Miller index and concomitant step density, whereas experimental results correspond to an ensemble of facets, yielding an average step density.…”

“…Jansen and Juurlink have also determined the step sticking cross section of the (100)-like step in a curved Pt crystal. 54 At a low incidence energy, the sticking probability of D 2 on Pt presumably originates solely from the steps and only from molecules impacting the surface on or close to the step 53 and rapidly decays with the incidence energy. Therefore, site specific sticking probabilities (i.e., S 0 step and S 0 terrace ) can be determined from the overall sticking probability S 0 as a function of incidence energy E i as follows: 54 where a – d are parameters fitted to the sticking probability and f step and f terrace are the fractions of the surface unit cell covered in steps and terraces, respectively.…”

“… 54 At a low incidence energy, the sticking probability of D 2 on Pt presumably originates solely from the steps and only from molecules impacting the surface on or close to the step 53 and rapidly decays with the incidence energy. Therefore, site specific sticking probabilities (i.e., S 0 step and S 0 terrace ) can be determined from the overall sticking probability S 0 as a function of incidence energy E i as follows: 54 where a – d are parameters fitted to the sticking probability and f step and f terrace are the fractions of the surface unit cell covered in steps and terraces, respectively. Then, the step sticking cross section ( A step S 0 step ) can be determined as follows: 54 where w step is the width of the unit cell along the step edge and d step is the step density.…”

“…Therefore, site specific sticking probabilities (i.e., S 0 step and S 0 terrace ) can be determined from the overall sticking probability S 0 as a function of incidence energy E i as follows: 54 where a – d are parameters fitted to the sticking probability and f step and f terrace are the fractions of the surface unit cell covered in steps and terraces, respectively. Then, the step sticking cross section ( A step S 0 step ) can be determined as follows: 54 where w step is the width of the unit cell along the step edge and d step is the step density. Note that the site specific sticking probabilities obtained from eq 1 are employed only when calculating the step sticking cross section with eq 2 (e.g., in Figure 2 b).…”