Fig. 2: Regulation of single-atom alloy Ni(111)-based catalysts.

a aggregation energy, \(\Delta {E}_{{agg}}\) (eV), of dimers and trimers dopants formation into Ni host. \(\Delta {E}_{{agg}} > \) 0.0 eV symbols for the propensity towards occupying isolated single sites, whereas \(\Delta {E}_{{agg}} < \) 0.0 eV designates favoring dimer or trimer aggregation. b screening of SAA catalysts based on segregation energy (\(\Delta {E}_{{seg}}\)), carbon clustering (\(\Delta {E}_{{rxn}{,}_{4C}}\)), and market price. Segregation energy indicates dopant surface segregation tendency or bulk occupancy (\(\Delta {E}_{{seg}} > \) 0 eV: favorable; \(\Delta {E}_{{seg}} < \) 0 eV: undesirable). Vertical axis: reaction energy of forming 4C^* chain (\(\Delta {E}_{{rxn}}{,}_{4C}\)). Less negative \(\Delta {E}_{{rxn}}{,}_{4C}\) indicates higher resistance to coking on the M-Ni surfaces. The inset depicts 4C optimized conformation on SAA M-Ni surfaces. Color bar represents SAA combinations prices; (i.e., M-Ni_($·Kg⁻¹) = Dopant_($·Kg⁻¹)\(\times\)0.0156+Ni_($·Kg⁻¹) \(\times\)(1−0.0156)). Cost-effective SAA M-Ni catalysts are ones with price \( < \)1500 $·Kg^-1. c surface energy, \({\gamma }_{M-{Ni}(111)}\) (J·m⁻²), of bimetallic single-atom alloy M-Ni(111) surfaces. Red values denote M-Ni mixtures less stable than Ni(111) (i.e., \({\gamma }_{M-{Ni}(111)}\ge {\gamma }_{{Ni}(111)}\)). Solid blackline, \({\gamma }_{{Ni}(111)}\) = 1.86 J·m⁻². d Hydrogen induced segregation energy compared with vacuum segregation of SAA M-Ni surfaces. 3H*-adsorbed on the 1^st nearest neighbor hcp-hollow sites simulate the M-dopants \(\Delta {E}_{{seg}}\) after rapid bio-oil dehydrogenation to H₂ production. Inserted figures denote the SAA configurations top views in the distinct environments. Single-atom dopants in a, b, and d are arranged by their d-series from right to left (IIIB to IIB group), then up to down (3 d to 5 d). Data available in Zenodo.