State-of-the-art processes to directly
convert methane into CH3Cl are run under corrosive conditions
and typically yield
a mixture of chloromethanes requiring subsequent separation. We report
a mechanochemical strategy to selectively convert methane to chloromethane
under overall benign conditions, employing trichloroisocyanuric acid
(TCCA) as a cheap and noncorrosive solid chlorinating agent. TCCA
is shown to release active chlorine species upon milling with Lewis
acids such as alumina and ceria to functionalize methane at moderate
temperatures (<150 °C). A thorough parameter optimization
led to a maximum methane chlorination rate of 0.8 μmol(CH4,conv) (g(catalyst) s)−1. Findings were
compared to the thermal reaction of methane with TCCA and evidenced
that mechanochemical activation permitted significantly lower reaction
temperatures (90 vs 200 °C) at a drastically improved CH3Cl selectivity (95% vs 66% at 30% conversion). Considering
the characterization of the interaction between TCCA and Lewis acids
as well as the in-depth analysis of byproducts, we suggest a plausible
reaction mechanism and a possible regeneration of the chlorinating
agent.
Hydrogen generated in electrolyzers is discussed as a key element in future energy scenarios, but oxygen evolution as the standard anode reaction is a complex multi‐step reaction requiring a high overpotential. At the same time,it does not add value‐the oxygen is typically released into the atmosphere. Alternative anode reactions which can proceed at similar current densities as the hydrogen evolution are, therefore, of highest interest. We have discovered a high‐performance electrode based on earth‐abundant elements synthesized in the presence of H
2
O
2
, which is able to sustain current densities of close to 1 A cm
−2
for the oxidation of many organic molecules, which are partly needed at high production volumes. Such anode reactions could generate additional revenue streams, which help to solve one of the most important problems in the transition to renewable energy systems, i.e. the cost of hydrogen electrolysis.
The electrochemical oxidation of 5-(hydroxymethyl)furfural (HMF) to 2,5-furandicarboxylic acid (FDCA), a monomer for biopolymer production, caught attention as a route to renewable materials. However, this process is mostly performed in...
Electrooxidation. A novel electrode for value‐generating anode reactions in water electrolyzers at industrial current densities is reported by Yufeng Wu, Ferdi Schüth et al. in their Communication (e202215804).
Two approaches for the synthesis of the triethylenediamine (TEDA) · AlH 3 adduct have been discovered. Both, the mechanochemical procedure and the wet chemical method lead to crystalline products. Starting from metallic Al powder and TEDA, ball milling under a pressure of 100 bar H 2 facilitates a direct hydrogenation of aluminum with conversions up to 90 %. Structure determination from X-ray powder diffraction data revealed an 1-D-coordination polymer of the type [TEDAÀ AlH 3 ] n .Furthermore, solid-state NMR techniques have been applied to analyze composition and structure of the products. Due to the polymeric arrangement, an enhanced stability of the material occurred which was investigated by thermal analysis showing a decomposition located above 200°C. Overall, the stabilization of AlH 3 by TEDA holds promise for hydrogen storage applications.
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