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It is desirable to design nonprecious metal nanocatalysts with high stability and catalytic performance for fine chemicals production. Here, a method is reported for the preparation of cobalt metal and cobalt oxide cores confined within nanoporous nitrogen‐doped hollow carbon capsules. Core–shell structured Zn/Co‐ZIF@polymer materials are fabricated through a facile coating polymer strategy on the surface of zeolitic imidazolate frameworks (ZIF). A series of hollow carbon capsules with cobalt metal and cobalt oxide are derived from a facile confined pyrolysis of Zn/Co‐ZIF@polymer. The hollow Co‐CoOx@N‐C capsules can prevent sintering and agglomeration of the cobalt nanoparticles and the nanoporous shell allows for efficient mass transport. The specific surface area and Co particle size are optimized through finely tuning the original Zn content in ZIF particles, thus enhancing overall catalytic activity. The yolk–shell structured Zn4Co1Ox@carbon hollow capsules are shown to be a highly active and selective catalyst (selectivity >99%) for hydrogenation of nitrobenzene to aniline. Furthermore, Zn4Co1Ox@carbon hollow particles show superior catalytic stability, and no deactivation after 8 cycles of reaction. The hollow Co‐CoOx@N‐C capsules may shed light on a green and sustainable catalytic process for fine chemicals production. [ABSTRACT FROM AUTHOR]

Catalytic hydrogenation of carbon dioxide to CO by reverse water gas shift reaction plays a vital role in the recycling of the abundant carbon source. Here, the reaction over a series of zeolite L-supported platinum catalysts was systematically investigated to study the promoting role of potassium. The results of activity tests showed that controlled addition of potassium promoter to Pt/L catalyst was beneficial for the catalytic activity and selectivity. It was observed that cage encapsulation by zeolite pores could stabilize Pt nano-particles even at severe reaction conditions. Furthermore, X-ray absorption near edge structure and X-ray photoelectron spectra results demonstrated that the chemical state of platinum was altered by the additional potassium promoter, providing evidence for the formation of Pt-O(OH)-K interfacial sites. Thereafter, the Pt-O(OH)-K interfaces, acting as main active sites to adsorb CO 2 and produce bridge-bonded formate intermediates, were identified by a set of in-situ diffuse reflectance Fourier transform infrared spectroscopy and microcalorimetry measurements. This finding provides new insights into the use of a variety of zeolite as carriers for highly dispersed noble metal in catalytic CO 2 reduction. [ABSTRACT FROM AUTHOR]