Fig. 1: Hierarchical DFT descriptor-based assessment criteria for the discovery of promising single-atom alloys (SAA) Ni-based catalysts for bio-oil upgrading to hydrogen.

From top to bottom in the figure, the 26-dopants are screened based on their (1) stability: aggregation energy (\(\Delta {E}_{{agg}}\)), segregation energy (\(\Delta {E}_{{seg}}\)), surface energy (\(\gamma\)), carbon-clustering; 4 C^* reaction energy (\(\Delta {E}_{{rxn}{,}_{4C}}\)), and price ($·kg⁻¹). Then, (2) acetic acid adsorption (\({E}_{{{ads},}_{C{H}_{3}{COOH}}}\)) and dehydrogenation (\(\Delta {E}_{{rxn}}\)) energies are assessed. (3) H₂ production activity is evaluated based on 2H^* adsorption energy (\({E}_{{ads}{,}_{2H}}\)) and \(\Delta {E}_{{rxn}}\) of 2H^*\(\to\)H₂^*_. The SAA catalysts’ (4) coke formation and regeneration are considered through C^* and O^* adsorption energies (\({E}_{{ads}{,}_{C+O}}\)) and \(\Delta {E}_{{rxn}}\) of C^* + O^* \(\to\) CO^*. Steam reforming is captured through (5) water dissociation (\(\Delta {E}_{{rxn}}\) of H₂O^*\(\to\)H^* + OH^*) and H^* and OH^* adsorption energy (\({E}_{{ads}{,}_{H+{OH}}}\)). Finally, screening of trimetallic combinations is executed to provide novel SAA M₁-M₂-Ni catalysts candidates. Inserted figures denote the bimetallic and trimetallic SAA Ni-based configurations.