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1. Effect of nickel phosphide phase on the photo-thermal catalytic hydrogenation of carbon dioxide

   https://doi.org/10.1016/j.cattod.2025.115185  

   Hennig, Hannah K; Schare, Jacob R; Lynch, Reilly P; Bullock, Alex; Baldwin, Michael S; Bussell, Mark E (April 2025, Catalysis Today)

   Khatib, Sheima J; Groppo, Elena (Ed.)

   The CO2 hydrogenation (HYD) reaction was investigated over Ni phosphide (Ni3P, Ni12P5, Ni2P) catalysts to probe the effect of the NixPy phase on photo-thermal catalytic properties in comparison to Ni metal. The light absorption properties of 2.5 wt% NixPy/SiO2 catalysts differ substantially, with the extent of light absorption decreasing as the P/Ni molar ratio of the Ni phosphide phase increases. This finding directly impacts the photo-thermal catalytic properties as the photo-enhancement (light activity / dark activity) correlates linearly with the extent of light absorption. For comparison purposes, 2.5 wt% Ni/SiO2 catalysts were also investigated and showed high activity but suffered from low CO selectivity (57-68%). A Ni3P/SiO2 catalyst was the most active of the Ni phosphides with high CO selectivity (>95%), while Ni12P5/SiO2 and Ni2P/SiO2 catalysts had lower CO2 HYD activities but CO selectivities above 98%. Upon light exposure, the NixPy/SiO2 (and Ni/SiO2) catalysts exhibited significant rises of temperature (~200 K increase from room temperature), indicating the importance of photothermal heating in increasing the CO2 HYD rate. The findings highlight how a non-metal element (i.e., P) plays a crucial role in tailoring the photo-thermal catalytic properties of earth abundant nickel metal. 

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2. A hybrid lipid membrane coating “shape-locks” silver nanoparticles to prevent surface oxidation and silver ion dissolution

   https://doi.org/10.1039/D0RA01727B  

   Miesen, Thomas J.; Engstrom, Arek M.; Frost, Dane C.; Ajjarapu, Ramya; Ajjarapu, Rohan; Lira, Citlali Nieves; Mackiewicz, Marilyn R. (April 2020, RSC Advances)

   null (Ed.)

   The controlled synthesis of stable silver nanoparticles (AgNPs), that do not undergo surface oxidation and Ag + ion dissolution, continues to be a major challenge. Here the synthesis of robust hybrid lipid-coated AgNPs, comprised of l -α-phosphatidylcholine (PC) membranes anchored by a stoichiometric amount of long-chained hydrophobic thiols and sodium oleate (SOA) as hydrophobic binding partners, that do not undergo surface oxidation and Ag + ion dissolution, is described. UV-Visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), and inductively coupled plasma mass spectrometry (ICP-MS) demonstrate that in the presence of strong oxidants, such as potassium cyanide (KCN), the hybrid lipid-coated AgNPs are stable and do not undergo surface oxidation even in the presence of membrane destabilizing surfactants. UV-Vis studies show that the stability of hybrid lipid-coated AgNPs of various sizes and shapes is dependent on the length of the thiol hydrocarbon chain and can be ranked in the order of increasing stability as follows: propanethiol (PT) < hexanethiol (HT) ≤ decanethiol (DT). UV-Vis and ICP-MS studies show that the hybrid lipid-coated AgNPs do not change in size or shape confirming that the AgNPs do not undergo surface oxidation and Ag + ion dissolution when placed in the presence of strong oxidants, chlorides, thiols, and low pH. Long-term stability studies, over 21 days, show that the hybrid lipid-coated AgNPs do not release Ag + ions and are more stable. Overall, these studies demonstrate hybrid membrane encapsulation of nanomaterials is a viable method for stabilizing AgNPs in a “shape-locked” form that is unable to undergo surface oxidation, Ag + ion release, aging, or shape conversion. More importantly, this design strategy is a simple approach to the synthesis and stabilization of AgNPs for a variety of biomedical and commercial applications where Ag + ion release and toxicity is a concern. With robust and shielded AgNPs, investigators can now evaluate and correlate how the physical features of AgNPs influence toxicity without the confounding factor of Ag + ions present in samples. This design strategy also provides an opportunity where the membrane composition can be tuned to control the release rate of Ag + ions for optimizing antimicrobial activity. 

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3. New monoclinic ruthenium dioxide with highly selective hydrogenation activity

   https://doi.org/10.1039/d2cy00815g  

   Yang, Hee Jung; Redington, Morgan; Miller, Daniel P.; Zurek, Eva; Kim, Minseob; Yoo, Choong-Shik; Lim, Soo Yeon; Cheong, Hyeonsik; Chae, Seen-Ae; Ahn, Docheon; et al (October 2022, Catalysis Science & Technology)

   Catalytic hydrogenation of aromatic compounds is an important industrial process, particularly for the production of many petrochemical and pharmaceutical derivatives. This reaction is mainly catalyzed by noble metals, but rarely by metal oxides. Here, we report the development of monoclinic hydrogen-bearing ruthenium dioxide with a nominal composition of H x RuO 2 that can serve as a standalone catalyst for various hydrogenation reactions. The hydrogen-bearing oxide was synthesized through the water gas shift reaction of CO and H 2 O in the presence of rutile RuO 2 . The structure of H x RuO 2 was determined by synchrotron X-ray diffraction and density functional theory (DFT) studies. Solid-state 1 H NMR and Raman studies suggest that this compound possesses two types of isolated interstitial protons. H x RuO 2 is very active in hydrogenation of various arenes, including liquid organic hydrogen carriers, which are completely converted to the corresponding fully hydrogenated products under relatively mild conditions. In addition, high selectivities (>99%) were observed for the catalytic hydrogenation of functionalized nitroarenes to corresponding anilines. DFT simulations yield a small barrier for concerted proton transfer. The facile proton dynamics may be key in enabling selective hydrogenation reactions at relatively low temperature. Our findings inspire the search for hydrogen-containing metal oxides that could be employed as high-performance materials for catalysts, electrocatalysts, and fuel cells. 

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4. Traceless native chemical ligation of lipid-modified peptide surfactants by mixed micelle formation

   https://doi.org/10.1038/s41467-020-16595-w  

   Jin, Shuaijiang; Brea, Roberto J.; Rudd, Andrew K.; Moon, Stuart P.; Pratt, Matthew R.; Devaraj, Neal K. (June 2020, Nature Communications)

   Abstract Biology utilizes multiple strategies, including sequestration in lipid vesicles, to raise the rate and specificity of chemical reactions through increases in effective molarity of reactants. We show that micelle-assisted reaction can facilitate native chemical ligations (NCLs) between a peptide-thioester – in which the thioester leaving group contains a lipid-like alkyl chain – and a Cys-peptide modified by a lipid-like moiety. Hydrophobic lipid modification of each peptide segment promotes the formation of mixed micelles, bringing the reacting peptides into close proximity and increasing the reaction rate. The approach enables the rapid synthesis of polypeptides using low concentrations of reactants without the need for thiol catalysts. After NCL, the lipid moiety is removed to yield an unmodified ligation product. This micelle-based methodology facilitates the generation of natural peptides, like Magainin 2, and the derivatization of the protein Ubiquitin. Formation of mixed micelles from lipid-modified reactants shows promise for accelerating chemical reactions in a traceless manner. 

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5. Enhancing Phenol Adsorption on Hydrophobic Pd/SiO2 to Achieve Faster and More Selective Hydrogenation

   https://doi.org/10.1007/s11244-023-01851-2  

   Chalmers, Jason A.; Moon, Hyunjin; Ausman, Samantha F.; Chuang, Cheng-Hsun; Scott, Susannah L. (January 2023, Topics in Catalysis)

   The effect of catalyst hydrophobicity on the kinetics of hydrogenation of aqueous phenol was investigated. The hydrophobicity of a Pd/SBA-15 catalyst was altered by synthesizing an organosilane with biphenylene framework linkers. Partitioning of phenol between the aqueous solution and the pores favors the hydrophobic catalyst by an order of magnitude at room temperature, relative to the hydrophilic catalyst. The rate of hydrogenation at 75 °C is higher in the hydrophobic catalyst, as is the selectivity for the partial hydrogenation product, cyclohexanone. Analysis of kinetic profiles measured using operando 13C NMR reveals that the hydrophobic catalyst has a larger apparent (i.e., composite) adsorption constant for phenol, which results in higher phenol surface coverage and, consequently, faster and more selective hydrogenation to cyclohexanone. 

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