Plasma-Assisted Dinitrogen Activation via Dual Platinum Cluster Catalysis:A Strategy for Ammonia Synthesis under Mild Conditions

The activation and reduction of N_(2)to produce ammonia under mild conditions is of great interest,but challenges remain.Here,we report a breakthrough in efficient dinitrogen cleavage by employing small Ptn+(n=1–4)clusters and convenient plasma assistance.The reactivity of Pt3+is found to be substantially higher than that of other clusters,and the formed Pt3N7+shows prominent mass abundance among the odd-nitrogen products.We illustrate that a chain reaction path within dual cluster cooperation,especially via a“3+2”mode,is beneficial to N≡N triple bond dissociation,embodying efficient synergistic catalysis.A key intermediate containing a bridged N_(2)of binding with two Pt clusters facilitates N_(2)activation with significantly enhanced interactions between the d orbitals of Pt and the antibondingπ*-orbitals of N_(2).Furthermore,by reacting the Pt_(n)N_(m)+clusters with H_(2),we observed hydrogenation products of both evenand odd-hydrogen species,indicative of ammonia release.The in situ synthesized platinum nitride clusters,typically Pt_(3)N_(7)+,induce a highly active N site for hydrogen anchoring,enabling a cost-effective hydrotreating process for ammonia synthesis.

Co_(12)C^(-)_(12)--metallo-carbospherenes:a new class of magic clusters for hydrogen storage

Metal carbides play significant roles in electronics and materials science due to their unique properties,high strength,and high melting points.Also,they are applied in various organometallic synthesis and catalytic reactions,such as in the Fischer-Tropsch process and olefin metathesis[1,2],and they are able to adsorb small gas molecules such as hydrogen showing promising application for the hydrogen storage[3].Hydrogen is known as a sustainable solution for rising energy demands and an environmentally friendly option to replace fossil fuels.Enormous efforts have been made to develop hydrogen storage materials[4],with the aim to facilitate the application of hydrogen energy for achieving the future carbon–neutral goal set by governments.It has been recognized that the removal of the metal-bound terminal ligands and the doping of transition metals(TMs)on carbon substrates can improve the capacity of hydrogen adsorption[5,6].

Single-electromagnet levitation for density measurement and defect detection

This paper presents a single-electromagnet levitation device to measure the densities and detect the internal defects of antimagnetic materials.The experimental device has an electromagnet in its lower part and a pure iron core in the upper part.When the electromagnet is activated,samples can be levitated stably in a paramagnetic solution.Compared with traditional magnetic levitation devices,the single-electromagnet levitation device is adjustable.Different currents,electromagnet shapes,and distances between the electromagnet and iron core are used in the experiment depending on the type of samples.The magnetic field formed by the electromagnet is strong.When the concentration of the MnCl aqueous solution is 3 mol/L,the measuring range of the single-electromagnet levitation device ranges from 1.301 to 2.308 g/cm.However,with the same concentration of MnCl aqueous solution(3 mol/L),the measuring range of a magnetic levitation device built with permanent magnets is only from 1.15 to 1.50 g/cm.The single-electromagnet levitation device has a large measuring range and can realize accurate density measurement and defect detection of high-density materials,such as glass and aluminum alloy.

Pure Metal Clusters with Atomic Precision for Nanomanufacturing

Advances in cluster science have enabled the preparation of atomically precise metal clusters with one to a hundred atoms under controllable expansion conditions.After introducing typical gas-phase cluster preparation and reaction apparatuses,this work summarized recent progress in preparing pure metal clusters of single-atom resolution,including neutral and ionic ones,with typical examples of Al,V,Nb,Fe,Co,Ni,Rh,Pt,Ag,Cu,and Pb.With the development of soft-landing deposition technology,the size-selective pure metal clusters with strict atomic precision and predictive property will benefit nanomanufacturing down to atomic and near-atomic scales.This work serves as a modest motivation to stimulate the interest of scientists focusing on interdisciplinary subjects.