Nitric oxide (NO) emitted from coal-fired power plants has raised global concerns.

The fabrication of intrinsic carbon defects is usually tangled with doping effects, and the identification of their unique roles in catalysis remains a tough task. Herein, a K+‐assisted synthetic strategy is developed to afford porous carbon (K‐defect‐C) with abundant intrinsic defects and complete elimination of heteroatom via direct pyrolysis of K+‐confined metal–organic frameworks (MOFs). Positron‐annihilation lifetime spectroscopy, X‐ray absorption fine structure measurement, and scanning transmission electron microscopy jointly illustrate the existence of abundant 12‐vacancy‐type carbon defects (V12) in K‐defect‐C. Remarkably, the K‐defect‐C achieves ultrahigh CO Faradaic efficiency (99%) at −0.45 V in CO2 electroreduction, far surpassing MOF‐derived carbon without K+ etching. Theoretical calculations reveal that the V12 defects in K‐defect‐C favor CO2 adsorption and significantly accelerate the formation of the rate‐determining COOH* intermediate, thereby promoting CO2 reduction. This work develops a novel strategy to generate intrinsic carbon defects and provides new insights into their critical role in catalysis.

Selective hydrogenation with high efficiency under ambient conditions remains a long-standing challenge. Here, a yolk−shell nanostructured catalyst, PdAg@ZIF-8, featuring plasmonic PdAg nanocages encompassed by a metal−organic framework (MOF, namely, ZIF-8) shell, has been rationally fabricated. PdAg@ZIF-8 achieves selective (97.5%) hydrogenation of nitrostyrene to vinylaniline with complete conversion at ambient temperature under visible light irradiation. The photothermal effect of Ag, together with the substrate enrichment effect of the catalyst, improves the Pd activity. The near-field enhancement effect from plasmonic Ag and optimized Pd electronic state by Ag alloying promote selective adsorption of the −NO 2 group and therefore catalytic selectivity. Remarkably, the unique yolk−shell nanostructure not only facilitates access to PdAg cores and protects them from aggregation but also benefits substrate enrichment and preferential −NO 2 adsorption under light irradiation, the latter two of which surpass the core−shell counterpart, giving rise to enhanced activity, selectivity, and recyclability.

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