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Developing the alternative supported noble metal catalysts with low cost, high catalytic efficiency, and good resistance toward carbon dioxide and water vapor is critically demanded for the oxidative removal of volatile organic compounds (VOCs). In this work, we prepared the mesoporous chromia-supported bimetallic Co and Ni single-atom (Co1Ni1/meso-Cr2O3) and bimetallic Co and Ni nanoparticle (CoNPNiNP/meso-Cr2O3) catalysts adopting the one-pot polyvinyl pyrrolidone (PVP)- and polyvinyl alcohol (PVA)-protecting approaches, respectively. The results indicate that the Co1Ni1/meso-Cr2O3 catalyst exhibited the best catalytic activity for n-hexane (C6H14) combustion (T50% and T90% were 239 and 263 °C at a space velocity of 40,000 mL g−1 h−1; apparent activation energy and specific reaction rate at 260 °C were 54.7 kJ mol−1 and 4.3 × 10−7 mol gcat−1 s−1, respectively), which was associated with its higher (Cr5+ + Cr6+) amount, large n-hexane adsorption capacity, and good lattice oxygen mobility that could enhance the deep oxidation of n-hexane, in which Ni1 was beneficial for the enhancements in surface lattice oxygen mobility and low-temperature reducibility, while Co1 preferred to generate higher contents of the high-valence states of chromium and surface oxygen species as well as adsorption and activation of n-hexane. n-Hexane combustion takes place via the Mars−van Krevelen (MvK) mechanism, and its reaction pathways are as follows: n-hexane → olefins or 3-hexyl hydroperoxide → 3-hexanone, 2-hexanone or 2,5-dimethyltetrahydrofuran → 2-methyloxirane or 2-ethyl-oxetane → acrylic acid → COx → CO2 and H2O.

Chlorinated volatile organic compounds (CVOCs) are persistent pollutants and harmful to the atmosphere, environment, and human health. The catalytic elimination of CVOCs has become a hotspot of interest due to their self-toxicity, the secondary generation of chlorinated by-products, and the Cl poisoning of catalysts. The development of high-performance, highly selective, and anti-poisoning catalysts is a critical issue. Bimetallic catalysts exhibit an improved dechlorination performance, poisoning resistance, and product selectivity through the modulation of geometrical and electronic structures. The present review article gives a brief overview of the recent advancements in the preparation of bimetallic catalysts and their catalytic CVOC elimination activities. In addition, representative case studies are provided to investigate the physicochemical properties, CVOC conversion, COx and inorganic chlorine species selectivities, and by-product control so that the structure–performance relationships of bimetallic catalysts can be established. Furthermore, this review article provides a fundamental understanding of designing bimetallic catalysts with specific active components and the desired physicochemical properties for target reactions. In the end, related perspectives for future work are proposed.

Intermetallic compounds (IMCs) have attracted significant attention in recent years due to their unique properties and potential applications in various fields, particularly in catalysis. This review aims to provide an in-depth understanding of IMCs, including their synthesis methods, structural characteristics, and diverse catalytic applications. The review begins with an introduction to IMCs, highlighting their distinct features and advantages over traditional catalyst materials. It then delves into the synthesis techniques employed to prepare IMCs and explores their structural properties. Subsequently, catalytic applications of the IMCs are introduced, focusing on the key reactions and highlighting their superior catalytic performance compared to conventional catalysts. Future perspectives for, and challenges to, the catalysis of IMCs are then proposed.