In situ deposited copper nanodendrites are herein proven to be a highly selective electrocatalyst which is capable of reducing CO2 to ethylene by reaching a Faradaic efficiency of 57% at a current density of 170 mA cm−2. It is found that the desired structures are formed in situ under acidic pH conditions at high electrode potentials more negative than −2 V versus Ag/AgCl. Detailed investigations on the preparation, characterization, and advancement of electrode materials and of the electrolyte have been performed. Catalyst degradation effects are intensively followed by scanning electron microscopy (SEM) and high‐resolution transmission electron microscopy (HR‐TEM) characterization methods and found to be a major root course for selectivity losses.

The industrialization of the electrochemical reduction of CO 2 toward CO in aqueous electrolytes has recently been started using silver-based gas diffusion electrodes. The performance of a CO 2 -to-CO electrolyzer model on a 10-cm 2 cell size is assessed with respect to operating pressure, achievable current density at faradaic efficiency of CO above 90 %, composition of gas streams and operational lifetime. Operational lifetime has exceeded 1500 h. The first scaling step to 300 cm 2 has been accomplished. The rated power of such a cell is around 300 W.

Employing Ag2Cu2O3, a mixed metal oxide, as a template catalyst material for electrochemical reduction of CO enables generation of multi-carbon products with a faradaic efficiency of close to 92%, at a current density of 600 mA cm−2.

More than a decade ago, following the great interest shown by the automotive industry in hydrogen fuel-cell propelled vehicles, a quest for chemical-based hydrogen-storage and hydrogen-source systems exceeding the capacity of classical metal hydrides and complex metal hydrides began. As a compound with one of the highest hydrogen contents, ammonia borane (AB) was quickly identified as a promising candidate, especially because of its benign hydrogen-release temperatures starting at 95 8C. [1,2] The hydrogen release is exothermic, which explains why direct re-hydrogenation of spent AB is impossible. This low dehydrogenation temperature and the exothermicity both result from the simultaneous presence of hydridic and protic hydrogen in the AB molecule.Early suggestions of recycling procedures contain three important steps that pose great challenges for their practical implementation; namely: 1) the digestion of the polymeric spent AB by the formation of oxidized, or more specifically, halogenated boron species, BX 3 (X = Cl, Br,

A copper‐oxide‐based catalyst enriched with paramelaconite (Cu4O3) is presented and investigated as an electrocatalyst for facilitating electroreduction of CO2 to ethylene and other hydrocarbons. Cu4O3 is a member of the copper‐oxide family and possesses an intriguing mixed‐valance nature, incorporating an equal number of Cu+ and Cu2+ ions in its crystal structure. The material is synthesized using a solvothermal synthesis route and its structure is confirmed via powder X‐ray diffraction, transmission electron microscope based selected area electron diffraction, and X‐ray photoelectron spectroscopy. A flow reactor equipped with a gas diffusion electrode is utilized to test a copper‐based catalyst enriched with the Cu4O3 phase under CO2 reduction conditions. The Cu4O3‐rich catalyst (PrC) shows a Faradaic efficiency for ethylene over 40% at 400 mA cm−2. At −0.64 versus reversible hydrogen electrode, the highest C2+/C1 product ratio of 4.8 is achieved, with C2+ Faradaic efficiency over 61%. Additionally, the catalyst exhibits a stable performance for 24 h at a constant current density of 200 mA cm−2.