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Strain engineering has emerged as a powerful approach in steering material properties. However, the mechanism and potential limitations remain poorly understood. Here we report that subtle changes in molecular configurations can profoundly affect, conducively or adversely, the catalytic selectivity and product turnover frequencies (TOFs) of CO 2 reduction reaction. Specifically, introducing molecular curvature in cobalt tetraaminophthalocyanine improves the multielectron reduction activity by favorable *CO hydrogenation, attaining methanol Faradaic efficiency up to 52 %. In stark contrast, strained iron phthalocyanine exacerbates *CO poisoning, leading to decreased TOF CO by >50 % at -0.5 V RHE and a rapid current decay. The uniform dispersion is crucial for optimizing electron transfer, while activity is distinctly sensitive to the local atomic environment around the active sites. Specifically, local strain either enhances binding to intermediates or poisons the catalytic sites. Our comprehensive analysis elucidates the intricate relationship between molecular structure and activities, offering insights into designing efficient heterogeneous molecular interfaces., (© 2024 Wiley-VCH GmbH.)

The design of efficient non-noble metal catalysts for CO 2 hydrogenation to fuels and chemicals is desired yet remains a challenge. Herein, we report that single Mo atoms with a MoN 3 (pyrrolic) moiety enable remarkable CO 2 adsorption and hydrogenation to CO, as predicted by density functional theory studies and evidenced by a high and stable conversion of CO 2 reaching about 30.4 % with a CO selectivity of almost 100 % at 500 °C and very low H 2 partial pressure. Atomically dispersed MoN 3 is calculated to facilitate CO 2 activation and reduces CO 2 to CO* via the direct dissociation path. Furthermore, the highest transition state energy in CO formation is 0.82 eV, which is substantially lower than that of CH 4 formation (2.16 eV) and accounts for the dominant yield of CO. The enhanced catalytic performances of Mo/NC originate from facile CO desorption with the help of dispersed Mo on nitrogen-doped carbon (Mo/NC), and in the absence of Mo nanoparticles. The resulting catalyst preserves good stability without degradation of CO 2 conversion rate even after 68 hours of continuous reaction. This finding provides a promising route for the construction of highly active, selective, and robust single-atom non-precious metal catalysts for reverse water-gas shift reaction., (© 2022 Wiley-VCH GmbH.)