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Developing the catalytic activity and selectivity of palladium (Pd) catalysts for acetylene hydrogenation is key importance in the chemical industry and remains a challenge to this day. Here, the catalytic performance of Pd catalysts are influenced by the Pd electronic structure, in turn, controlled by different heteroatom doped support. Different catalysts are prepared by ionic liquids (ILs) with different precursors, and catalytic activity of selective hydrogenation of acetylene was investigated. The Pd/NC catalyst exhibits extraordinary conversion, selectivity and stable for the hydrogenation of acetylene (94.6% acetylene conversion with 91.3% selectivity to ethylene). This remarkable catalytic performance of Pd/NC is mainly linked to nitrogen-doped (N-doped) changes the electronic structure of Pd nanoparticles, ensures the rapid desorption of ethylene and prevents the formation of unnecessary ethane by over hydrogenation (demonstrated by XPS and DFT). Our strategy of controlling the electronic structure of Pd can be widely used in the reactions that change the micro electrochemical properties of active metals. Graphic Abstract The selective hydrogenation of acetylene to ethylene over Pd/NC with excellent conversion and selectivity is investigated. The doping of nitrogen leads to the unique electronic structure of Pd on the Pd/NC catalyst, which influences the adsorption of ethylene and acetylene, thus promoting its catalytic activity.

The catalytic hydrodechlorination (HDC) technology exhibits great flexibility and safety under mild conditions, and shows extremely promising application prospects for the degradation of 4-Chlorophenol (4-CP). Prepare the N-doped phenolic resin carbon support (PMF) using phenol, melamine and formaldehyde as raw materials, and load Pd nanoparticles (NPs) on it. The XPS results indicate that the Pd/PMF-800 has a higher Pyridine-N (24.8%) and a higher Pd 0 /(Pd 2+ +Pd 0 ) ratio (65.4%). Moreover, the difference in electronegativity between the N atom and the resin carbon support enhances the binding energy between them. This enhancement promotes the nucleation of Pd NPs on the surface of the resin carbon support, thereby imparting higher stability to the Pd NPs. Due to these comprehensive advantages, Pd/PMF-800 has the highest dechlorination activity (k obs = 0.0594 min⁻¹) and stability (dechlorination rate is 91.56% after 5 cycle). Additionally, it also demonstrates efficient dehalogenation rates for 2-Chlorophenol and 4-Bromophenol. It can provide a catalyst that has high-efficiency dehalogenation performance, strong acid and alkali stability and adaptability, and can be recycled for the degradation of halogenated phenols in the environment.

Semi-hydrogenation of acetylene is of growing interest and popularity but subjects to a major challenge in selective hydrogenation to ethylene. Here, we report a strategy that uses graphdiyne (GDY) as a carrier to prepare single-cluster catalysts (SCCs), which on average clusters composed of three atoms (denoted as Pd 3 trimer) and applied it to the acetylene semi-hydrogenation in the presence of large amounts of ethylene. Based on experimental results and systematic quantum chemical research and computational screening, we found that there are multiple active Pd structures on GDY and the Pd 3 trimer anchored on GDY is a specific and durable cluster with great potential for accurate and efficient heterogeneous catalysis. The synergetic effects between neighboring atoms in Pd trimer guarantee easy desorption of ethylene and the absence of unselective hydride species thereby preventing excessive hydrogenation to generate unwanted byproducts, which is a crucial mechanism for the excellent selectivity of the catalyst. This new method for precise synthesis Pd clusters provides accurate ways for designing selective hydrogenation catalysts at the atomic scale.

Background Human embryonic stem cells (hESCs), as naturally pluripotent stem cells, constitute a pivotal cell source for cell replacement therapies. Yet, the generation of clinically compliant hESC lines under feeder-free and xeno-free conditions remains inefficient. Moreover, the derivation of hESCs from clinically surplus and discarded low-quality embryos using the standardized, translation-ready culture systems has not been reported. Methods By optimizing culture conditions and inner cell mass (ICM) isolation method, we developed a method that significantly improves the derivation efficiency of hESC lines from clinically surplus and discarded frozen-thawed embryos under feeder- and xeno-free conditions. The derivation protocol is operationally simple and easily standardized, with the reagents commercially available and of GMP-grade. Results Using this protocol, we successfully established 16 hESC lines. Among blastocysts with morphologically distinct ICMs of grades A and B, the derivation efficiency achieved approximately 60%, with all three grade A ICMs yielding viable hESC lines (100% derivation efficiency for grade A). Notably, for embryos with poorly developed ICMs (grade C), the derivation efficiency of hESC lines approached 30%, showing the protocol’s robustness across varying ICM quality. Adhering to GMP standards, we derived two clinical-grade hESC lines, which were demonstrated biological safety, sustained pluripotency, and the capacity for three-germ-layer differentiation. Conclusions Our study offers a robust, standardized, and simple method for deriving clinical-grade hESCs. Efficient derivation, propagation and banking of hESC lines from frozen-thawed embryos would offer a valuable cell source for advancing regenerative medicine, disease modeling, and drug development.