Organic molecular electrocatalyst based on 2,2'-dipyridylamine catalyzes the two-electron oxygen reduction reaction. This acid-compatible and inexpensive organic molecule can potentially be applied for distributed production of hydrogen peroxide in electrochemical cells while co-generating electric power. (cover) “2,2′-Dipyridylamine as Heterogeneous Organic Molecular Electrocatalyst for Two-Electron Oxygen Reduction Reaction in Acid Media”, ACS Applied Energy Materials, 2019, 2 (10), 7272-7278 [link]

Remarkable progress has been accomplished in the past decade in the development of platinum‐group‐metal‐free (PGM‐free) oxygen reduction reaction (ORR) catalysts, a highly attractive alternative to the incumbent precious‐metal‐based catalysts for polymer electrolyte fuel cells. Our article reviewed research efforts aimed at obtaining Fe‐based PGM‐free catalysts with high activity and improved long‐term stability, as well as at a better understanding of the nature of ORR active sites – a prerequisite for further successful development of this class of fuel cell materials. (back cover) “Progress in the Development of Fe‐Based PGM‐Free Electrocatalysts for the Oxygen Reduction Reaction”, Advanced Materials, 2019, 31 (31), 1806545 [link]

Metal-ligand interactions at the early stage of nucleation govern the formation kinetics of metal nanostructures. For the first time, the molecular structures of a series of palladium-ligand complexes are revealed and tied to the growth kinetics of 2D Pd nanostructures in solution phase. The structure of the crucial Pd-amine complex and the resulted rare dish-like 2D nanostructure are featured on the cover of the June issue of Nano Research in 2018. More details of the finding and the fantastic structure-activity relationship of 2D Pd sheets for formic acid oxidation can be found in our article: (front cover) X. Yin, M. Shi, K. S. Kwok, H. Yin, D. L. Gray, J. A. Bertke, H. Yang, “Dish-like higher-ordered palladium nanostructures through metal ion-ligand complexation”, Nano Research, 2018, 11 (6), 3442–3452 [link]

Heat released from exothermic reaction between a popular pair of capping ligands, long‐carbon chain amine and carboxylic acid, was used as the main energy source for the preparation of a variety of metal nanocrystals, which are illustrated on the Front Cover of ChemNanoMat. Uniform gold nanowires and nanoparticles, and concave tetrahedral Pd nanoparticles were synthesized using this self‐heating method. This synthetic route arises from the unique heating method from ligand‐based chemical reactions. More information can be found in the Communication by X. Yin, et al. (DOI: 10.1002/cnma.201500123).

Click here for a video clip of the self-heating synthesis approach demonstrates how to make gold nanowires in one minute. Youtube: How to Make Gold Nanowires in One Minute

Platinum group metal-free (PGM-free) ORR catalysts based on earth-abundant transition metal in the matrices of N-doped carbon can significantly reduce the cost of H2-air fuel cell and many other energy devices. This graphic art depicts the highly heterogeneous nature of the PGM-free catalysts with a highlighted FeNx site. The later has been proposed to be the active sites for oxygen reduction reaction (ORR). On the background, the SEM micrograph shows the complex structure of a PGM-free cathode in MEA. Current progress in this research field can be found in our Review published in Advanced Materials. Current progress in this research field can be found in our Review published in Advanced Materials (DOI: 10.1002/adma.201806545).

Infinite metal atom chain of alternatively connected Pd4(CO)4(OAc)4 paddlewheel molecules and Pt(acac)2 square-planar molecules. In this crystal structure, Pd (blue) and Pt (pink) atoms are closely packed into one-dimensional metal atom wires. This work demonstrates how we can manipulate metal complexes through the metallophilic interactions to build an infinite one-dimensional world. More information can be found in our Communication: “A new motif for infinite metal atom wires”, Angewandte Chemie International Edition, 2014, 53 (51), 14087–14091

2.6 ångström is the answer. This AFM micrograph shows the morphology of a palladium Hanoi Tower composed of atomically thin layers of Pd. The spontaneous formation of this unique 2D structure is controlled by a palladium carbonyl acetate complex at the molecular level. For the first time, the spontaneous formation of such complicated 2D structure was observed, with its formation mechanisms fully modeled at the molecular level.