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[Display omitted] • The authors perform systematic search for high-performance and cost-effective materials toward electrochemical applications for Co-P system via advanced structural prediction. • Current results identified several stable monolayers, such as CoP, Co 2 P, and Co 3 P 2. • Especially, CoP was predicted to become as potential HER catalyst and anode material. • The paper disclosed the possible multifunctional applications for Co x P y monolayers and provided some theoretical guidance in designing electrocatalysts and anode materials from 2D transition-metal materials used in electrochemical processes. Exploring high-performance and cost-effective materials for electrochemical applications to meet eco-friendly and sustainable energy demands remain as an urgent need all the time. Large specific surface area and robust chemical activity endow two-dimensional (2D) materials with the potential as excellent candidates for electrochemical applications. Herein, we systematically study the 2D morphology for the Co-P system via advanced structural search and identify a series of stable monolayers, such as CoP, Co 2 P, and Co 3 P 2. Detailed first-principle calculations reveal that these monolayers showcase inherent metallicity which benefits boosting the electrochemical process. For hydrogen evolution reactions (HER), the activity of CoP could reach 54 meV, which is comparable to that of Pt. As anode material potassium-ion batteries, CoP exhibits a suitable open circuit voltage and high capacity to store metal ion. This work disclosed the possible multifunctional applications for Co x P y monolayers and provided some theoretical guidance in designing electrocatalysts and anode materials from 2D transition-metal materials used in electrochemical processes. [ABSTRACT FROM AUTHOR]

The designed novel nickel and calcium dual-atomic site catalysts efficiently catalyze CO 2 reduction to methanol with high activity and selectivity due to the synergistic effect of Ni and Ca atoms. [Display omitted] • An efficient nickel and calcium dual-atomic site catalysts (Ni-Ca DACs) for electrocatalytic CO 2 reduction was proposed. • The Ni-Ca DACs can convert CO 2 into methanol with high activity and selectivity. • The dual-atomic active sites of Ni and Ca atoms provide the synergistic effect to largely stabilize the key intermediates *OCHO and *CHO for further CO 2 hydrogenation. • Adjacent Ni and Ca atoms tune the polarized charges and d-band center of metal reaction center. • The designed Ni-Ca DACs provide a new avenue for reducing or replacing use of the transition metals. Atomically dispersed transition metal sites embedded into nitrogen-doped graphene provide promising potential for the electrochemical CO 2 reduction to CO, but the catalytic efficiency for further hydrogenation to methanol is seriously restricted. Herein, combining the advantage of single transition metal, alkaline-earth metal, and multiple active sites, we designed nickel and calcium dual-atomic site catalysts (Ni-Ca DACs) supported on N-doped graphene to enable CO 2 hydrogenation. First-principles calculations reveal that the electron-rich Ni atom serves as the carbon adsorption site, and the adjacent Ca atom with electron-deficient properties acts as the oxygen adsorption site, which largely stabilizes many CH x O y species through the O-Ca bond, especially the *OCHO, thus facilitating CO 2 reduction. More importantly, a synergistic adsorption process on Ni-Ca sites promote the formation of *CHO species that is considered as the key intermediate for generation of multi-electron products. Different from the single Ni or Ca catalysts that produce mainly CO or HCOOH, the Ni-Ca DACs can selectively catalyze CO 2 reduction to CH 3 OH, with a low limiting potential of −0.52 V, while suppressing the hydrogen evolution reaction. The outstanding catalytic activity originates from the tuned polarized charge and d-band center of active sites by synergistic interaction of adjacent Ni and Ca atoms. [ABSTRACT FROM AUTHOR]