Zeolite-based catalyst hydrocracking of plastics is a potential strategy for mitigating the environmental impacts of plastic wastes and recycling valuable resources, but difficult mass transfer, low concentration of acid sites, and high cost are still barriers to their practical applications. In this paper, we report an excellent hydrocracking catalyst of ZSM-5 nanosheets (Ce/b-ZSM-5) modified by Ce species with high conversion up to 96.3%, C3-C5 selectivity up to 80.9%, and good stability during the hydrogenation of low-density polyethylene. Through comprehensive studies, b-ZSM-5 shows higher molecular diffusion efficiency and acid site concentrations compared with normal ZSM-5 (n-ZSM-5) and hollow ZSM-5 (h-ZSM-5). The introduction of Ce species into b-ZSM-5 further increases the density of Bronsted (B) and Lewis (L) acid sites as active sites, which enhances the adsorption of substrates and facilitates the formation of intermediates and desorption of products. As a result, the hydrocracking activity of Ce/b-ZSM-5 is significantly improved.

Hydrocracking catalysis is a key route to plastic waste upgrading, but the acid site-driven C−C cleavage step is relatively sluggish in conventional bifunctional catalysts, dramatically effecting the overall efficiency. We demonstrate here a facile and efficient way to boost the reactivity of acid sites by introducing Ce promoters into Pt/HY catalysts, thus achieving a better metal-acid balance. Remarkably, 100 % of low-density polyethylene (LDPE) can be converted with 80.9 % selectivity of liquid fuels over the obtained Pt/5Ce-HY catalysts at 300 °C in 2 h. For comparison, Pt/HY only gives 38.8 % of LDPE conversion with 21.3 % selectivity of liquid fuels. Through multiple experimental studies on the structure-performance relationship, the Ce species occupied in the supercage are identified as the actual active sites, which possess remarkably-improved adsorption capability towards short-chain intermediates.

Electrocatalytic CO2 reduction reaction (CO2 RR) is a promising and green approach for reducing atmospheric CO2 concentration and achieving high-valued conversion of CO2 under the carbon-neutral policy. In CO2 RR, the dual-site metal catalysts (DSMCs) have received wide attention for their ingenious design strategies, abundant active sites, and excellent catalytic performance attributed to the synergistic effect between dual-site in terms of activity, selectivity and stability, which plays a key role in catalytic reactions. This review provides a systematic summary and detailed classification of DSMCs for CO2 RR, describes the mechanism of synergistic effects in catalytic reactions, and also introduces in situ characterization techniques commonly used in CO2 RR. Finally, the main challenges and prospects of dual-site metal catalysts and even multi-site catalysts for CO2 recycling are analyzed. It is believed that based on the understanding of bimetallic site catalysts and synergistic effects in CO2 RR, well-designed high-performance, low-cost electrocatalysts are promising for achieving CO2 conversion, electrochemical energy conversion and storage in the future.

The reverse water‐gas shift reaction (RWGS) has been regarded as a promising approach for fighting climate change caused by the excessive emission of the greenhouse gas CO 2 , but it still suffers from relatively poor low‐temperature reactivity. Herein, a high‐performance RWGS catalyst composed of ultrasmall Pt clusters (1.38 nm on average) anchored by La 2 O 2 CO 3 support (Pt NC /LOC), which possesses a record CO production rate of 2678 mol CO mol Pt −1 h −1 with nearly 100% CO selectivity at 300 °C, is reported. The specific activity is nearly 1.5 and 7.9 fold higher than that of Pt single atoms and nanoparticles on La 2 O 2 CO 3 , respectively. More importantly, over 87.7% of the initial activity of Pt NC /LOC remains after 80 h constant operation at 380 °C, firmly verifying the structural robustness. LOC support is essential, because of not only the moderate basicity that can boost the reaction efficiency but also the strong interaction with Pt species that can stabilize the ultrasmall particle size. Further investigations also point out the key role of the Pt clusters. The two key steps, CO 2 adsorption, and CO desorption, individually prefer electron‐rich and electron‐deficient Pt species. Ultrasmall Pt clusters successfully integrate the unique surface states of single atoms and nanoparticles, thus achieving excellent low‐temperature RWGS performance.

选择性加氢在功能材料合成和化学产品提纯等化工领域中有非常重要的应用,并且近年来为减少温室效应的影响,将CO2催化选择性加氢转化成其他有应用价值的物质成为研究热点之一.其中热催化是应用较为广泛、易得到多种目标产物并且获得产品收率较高的方法.目前,利用CO2多相热催化加氢制得甲烷、甲醇、轻烯烃等多种高价值的燃料和化学品已取得了一定进展,但仍存在一些难点问题,其中制备高效催化剂是催化加氢反应的关键问题之一.一直以来,研究人员致力于解决催化剂的活性和选择性问题,通过助剂掺杂和加入功能性载体对催化剂进行改性.针对这些问题,本文简要介绍了 CO2催化加氢的研究背景,总结了近5年来热催化CO2加氢制得甲烷、甲醇、轻烯烃产品过程中使用催化剂的种类及对加氢反应的影响,期望为CO2多相催化加氢中新型催化剂的开发提供参考.

G old(Au) nanoclusters supported on various supports have been widely used in the fields of energy and catalysis. However, the poor thermal stability of Au nanoclusters on the support interface usually leads to a reduction or even loss of catalytic activity. Herein, we used an in situ reduction method to synthesize Au nanoclusters on ceria(CeO 2 ) carriers. In this method, sulfhydryl groups were used to modify CeO 2 nanospheres first, and then Au clusters with an average diameter of 1.5 nm were grown on the surface of ceria reduced with sodium borohydride. The presence of the Au-S-Ce structure enhances the electron transfer efficiency, making the material exhibit high CO oxidation activity at room temperature. Furthermore, due to the strong binding energy of S and Au, the material exhibits a high stability for long time running process. This strategy provides an idea for designing stable and active supported ultrasmall Au nanoclusters catalytic materials.