TY - JOUR
T1 - Does the breaking of adsorption-energy scaling relations guarantee enhanced electrocatalysis?
AU - Govindarajan, Nitish
AU - García-Lastra, Juan M.
AU - Meijer, Evert Jan
AU - Calle-Vallejo, Federico
PY - 2018
Y1 - 2018
N2 - The adsorption energies of numerous species on homogeneous and
heterogeneous catalysts scale linearly with each other. Such linear
dependence lowers the degrees of freedom in multistep reactions, greatly
simplifying computational electrocatalysis models. The downside of
scaling relations is that they limit the efficiency of electrocatalytic
reactions. For instance, the scaling relation between *OOH vs *OH
supposedly limits the oxygen evolution and reduction reactions (OER,
ORR): while the energetic separation of these intermediates should
ideally be 2.46 eV, on most catalysts it is ∼3.20 eV. Thus, it is
currently assumed that breaking such scaling relation might lead to
significant enhancement of OER/ORR electrocatalysis. In this review, we
evaluate this hypothesis using literature data. The analysis suggests
that breaking the *OOH vs *OH scaling relation is a necessary yet
insufficient condition to optimize OER/ORR electrocatalysts.
Alternatively, we define a new descriptor: the electrochemical-step
symmetry index (ESSI), the optimization of which effectively corresponds
to low calculated overpotentials.
AB - The adsorption energies of numerous species on homogeneous and
heterogeneous catalysts scale linearly with each other. Such linear
dependence lowers the degrees of freedom in multistep reactions, greatly
simplifying computational electrocatalysis models. The downside of
scaling relations is that they limit the efficiency of electrocatalytic
reactions. For instance, the scaling relation between *OOH vs *OH
supposedly limits the oxygen evolution and reduction reactions (OER,
ORR): while the energetic separation of these intermediates should
ideally be 2.46 eV, on most catalysts it is ∼3.20 eV. Thus, it is
currently assumed that breaking such scaling relation might lead to
significant enhancement of OER/ORR electrocatalysis. In this review, we
evaluate this hypothesis using literature data. The analysis suggests
that breaking the *OOH vs *OH scaling relation is a necessary yet
insufficient condition to optimize OER/ORR electrocatalysts.
Alternatively, we define a new descriptor: the electrochemical-step
symmetry index (ESSI), the optimization of which effectively corresponds
to low calculated overpotentials.
U2 - 10.1016/j.coelec.2018.03.025
DO - 10.1016/j.coelec.2018.03.025
M3 - Review
SN - 2451-9103
VL - 8
SP - 110
EP - 117
JO - Current Opinion in Electrochemistry
JF - Current Opinion in Electrochemistry
ER -