Can NOx reduction by CO react over carbon-based single-atom catalysts at
low temperatures? A theoretical study
First principles studies combined with the microkinetic analysis were
performed to study the reliability and reaction mechanisms of
single-atom doped graphene (SADGr) materials in catalyzing NOx reduction
with CO. By screening the 3d transition metals (Sc-Zn) and group-IV
elements (Si and Ge), it was found that the Ti and Co doped graphene
sheets (TiGr and CoGr) respectively own excellent catalytic activities
in the NO/NO2-to-N2O and the N2O-to-N2 processes at low temperatures.
Therefore, the TiGr/CoGr composite can be a promising catalyst in NOx
reduction with CO. It was further revealed the combination of adsorption
energy and electronegativity was a good descriptor to predict the
activation energies. The obtained results can provide useful information
for rational design of carbon-based single-atom catalysts for NOx
reduction by CO at low temperatures.