Designing high-performance catalysts is one of the major goals for material scientists. [1] One promising strategy is to explore a new metastable catalyst for its high-energy structure and high reactivity of unequilibrated metal surfaces. [1-3] However, the transformation from the higher-energy phase of metastable

Developing a versatile electrocatalyst with remarkable performance viable for pH-universal overall water splitting is increasingly important for the industrial production of renewable energy conversion. Herein, our theoretical calculations predicate that...

Non-metal-catalyzed C−H borylation of arenes represents a sustainable and environment-friendly approach for the functionalization of arenes. Despite its promise as an alternative to traditional transition-metal systems, its substrate scope is generally limited to electron-rich arenes, thus hindering its application in organic synthesis. Herein, we report the development of a borenium-ion catalyst which can borylate unactivated arenes under ambient conditions with 4-chlorocatecholborane (HBcat Cl ) as borylation reagent. This metal-free catalytic system is suitable for the borylation of C−H bonds in sterically encumbered positions, which has been a challenging task for transition-metal systems. Additionally, this catalytic system allows para-selective one-pot borylation of phenols, which has not been achieved by using transition-metal systems. Our mechanistic investigations and computational studies support a synergistic activation of the H−Bcat Cl bond by the arene substrate and the borenium-ion catalyst. This generates a Wheland intermediate and a neutral hydroborane species and is followed by deprotonation of the Wheland intermediate with the hydroborane species. The latter step of C−H bond cleavage is likely the rate-limiting step.

This review provides an overview of the recent advances in borenium-catalysed reactions with emphasis on catalyst synthesis, methodology development and mechanistic insight.

Although the water gas shift (WGS) reaction has sparked intensive attention for the production of high-purity hydrogen, the design of cost-efficient catalysts with noble metal-like performance still remains a great challenge. Here, we successfully overcome this obstacle by using Se-incorporated MoS 2 with a 1T phase. Combining the optimized electronic structure, additional active sites from edge sites, and a sulfur vacancy based on the 1T phase, as well as the high surface ratio from the highly open structure, the optimal MoS 1.75 Se 0.25 exhibits superior activity and stability compared to the conventional 2H-phase MoS 2 , with poor activity, large sulfur loss, and rapid inactivation. The hydrogen production of MoS 1.75 Se 0.25 is 942 μmol, which is 1.9 times higher than MoS 2 (504 μmol) and 2.8 times higher than MoSe 2 (337 μmol). Furthermore, due to the lattice stabilization via Se-incorporation, MoS 1.75 Se 0.25 exhibited excellent long-term stability without obvious change in more than 10 reaction rounds. Our results demonstrate a pathway to design efficient and cost-efficient catalysts for WGS.