The electrochemical conversion of N2 at ambient conditions using renewably generated electricity is an attractive approach for sustainable ammonia (NH3) production. Considering the chemical inertness of N2, rational design of efficient and stable catalysts is required. Therefore, in this work, it is demonstrated that a C‐doped TiO2/C (C‐TixOy/C) material derived from the metal–organic framework (MOF) MIL‐125(Ti) can achieve a high Faradaic efficiency (FE) of 17.8 %, which even surpasses most of the established noble metal‐based catalysts. On the basis of the experimental results and theoretical calculations, the remarkable properties of the catalysts can be attributed to the doping of carbon atoms into oxygen vacancies (OVs) and the formation of Ti−C bonds in C‐TixOy. This binding motive is found to be energetically more favorable for N2 activation compared to the non‐substituted OVs in TiO2. This work elucidates that electrochemical N2 reduction reaction (NRR) performance can be largely improved by creating catalytically active centers through rational substitution of anions into metal oxides.

A series of new bis(acyl)phosphane oxide (BAPO) photoinitiators has been synthesized and tested with respect to their efficiency in the initiation step of radical photopolymerizations. The transient absorption spectra of the phosphanoyl radicals obtained upon laser‐flash photolysis reveal maxima at ca. 450–460 nm. Rate constants for the addition of these radicals to the double bonds of butyl acrylate, methyl methacrylate, 1‐vinyl‐2‐pyrrolidone, and styrene have been determined. All phosphanoyl radicals have been found to react the most rapidly with styrene and the most slowly with butyl acrylate. Low fluorescence quantum yields of 0.1–0.3 % reveal that the studied BAPOs undergo efficient intersystem crossing, followed by α‐cleavage. The heat profiles of selected photopolymerizations have been observed using a high‐resolution infrared camera. Thermal‐imaging experiments show substantial monomer‐dependent exothermicity. All BAPO derivatives can additionally act as electron acceptors, as indicated by cyclic voltammetry and EPR spectroscopy.

The electrochemical conversion of low-cost precursors into high-value chemicals using renewably generated electricity is a promising approach to build up an environmentally friendly energy cycle, including a storage element. The large-scale implementation of such process can, however, only be realized by the design of cost-effective electrocatalysts with high efficiency and highest stability. Here, we report the synthesis of N and B codoped porous carbons. The constructed B–N motives combine abundant unpaired electrons and frustrated Lewis pairs (FLPs). They result in desirable performance for electrochemical N2 reduction reaction (NRR) and electrooxidation of 5-hydroxy­methylfurfural (HMF) in the absence of any metal cocatalyst. A maximum Faradaic efficiency of 15.2% with a stable NH3 production rate of 21.3 μg h–1 mg–1 is obtained in NRR. Besides, 2,5-furan­dicarboxylic acid (FDCA) is first obtained by using non-metal-based electrocatalysts at a conversion of 71% and with yield of 57%. Gas adsorption experiments elucidate the relationship between the structure and the ability of the catalysts to activate the substrate molecules. This work opens up deep insights for the rational design of non-metal-based catalysts for potential electrocatalytic applications and the possible enhancement of their activity by the introduction of FLPs and point defects at grain boundaries.

We show the synthesis of a redox-active quinone, 2methoxy-1,4-hydroquinone (MHQ), from a bio-based feedstock and its suitability as electrolyte in aqueous redox flow batteries. We identified semiquinone intermediates at insufficiently low pH and quinoid radicals as responsible for decomposition of MHQ under electrochemical conditions. Both can be avoided and/or stabilized, respectively, using H 3 PO 4 electrolyte, allowing for reversible cycling in a redox flow battery for hundreds of cycles.

We show the synthesis of a redox-active quinone, 2methoxy-1,4-hydroquinone (MHQ), from a bio-based feedstock and its suitability as electrolyte in aqueous redox flow batteries. We identified semiquinone intermediates at insufficiently low pH and quinoid radicals as responsible for decomposition of MHQ under electrochemical conditions. Both can be avoided and/or stabilized, respectively, using H 3 PO 4 electrolyte, allowing for reversible cycling in a redox flow battery for hundreds of cycles.