Ninefold coordination of hydrogen is very rare, and has been observed in two different hydride complexes comprising rhenium and technetium. Herein, based on a theoretical/experimental approach, we present evidence for the formation of ninefold H- coordination hydride complexes of molybdenum ([MoH9]3-), tungsten ([WH9]3-), niobium ([NbH9]4-) and tantalum ([TaH9]4-) in novel complex transition-me...

Performance of the thermally-driven metal hydride hydrogen compressor (MHHC) is defined by (a) its H2 compression ratio and maximum output pressure; (b) throughput productivity/average flow rate; (c) specific thermal energy consumption which determines efficiency. In earlier studies, focus R&D efforts was on optimisation design MH containers heat mass transfer in storage system aimed at shorten...

Project Scope Our goal is to develop a multiscale approach to model desorption and adsorption of hydrogen in complex metal hydrides. In this initial stage of the project, we started by using density-functional-theory quantum chemical calculations to study the structure of complex metal hydrides and the interactions of hydrogen with the metal atoms in these hydrides. We analyzed the crystal stru...

During the fabrication of niobium superconducting radio frequency (SRF) particle accelerator cavities procedures are used that chemically or mechanically remove the passivating surface film of niobium pentoxide (Nb2O5). Removal of this film will expose the underlying niobium metal and allow it to react with the processing environment. If these reactions produce hydrogen at sufficient concentrat...

Due to the high energy needed break N ? bond (945 kJ mol?1), a key step in ammonia production is activation of dinitrogen, which industry requires use transition metal catalysts such as iron (Fe) or ruthenium (Ru), combination with temperatures and pressures. Here we demonstrate transition-metal-free catalyst—potassium hydride-intercalated graphite (KH0.19C24)—that can activate dinitrogen at ve...

Abstract Transition‐metal‐mediated dinitrogen fixation has been intensively investigated. The employment of main group elements for this vital reaction recently sparked interest because new chemistry. We report ammonia synthesis via a chemical looping process mediated by transition‐metal‐free barium hydride (BaH 2 ). Experimental and computational studies reveal that the introduction hydrogen v...

Data-augmented high-throughput QM approach to compute pKa of transition metal hydride complexes with hDFT accuracy and low cost.

This work presents a model to determine productivity and heat consumption of hydrogen compression utilising metal hydrides (MH) by using Pressure – Composition Temperature (PCT) diagrams the MH materials at defined operating conditions temperatures pressures. The present Part I is focused on analysis performances several AB5- AB2-type intermetallic alloys which, when between 20 150 °C, provide ...