The use of hydrogen as a fuel requires both safe and robust technologies for its storage and transportation. Formic acid (FA) produced by the catalytic hydrogenation of CO2 is recognized as a potential intermediate H2 carrier. Herein, we present the development of a formate‐based H2 storage system that employs a Ru PNP‐pincer catalyst. The high stability of this system allows cyclic operation with an exceptionally fast loading and liberation of H2. Kinetic studies highlight the crucial role of the base promoter, which controls the rate‐determining step in FA dehydrogenation and defines the total H2 capacity attainable from the hydrogenation of CO2. The reported findings show promise for the development of practical technologies that use formic acid as a hydrogen carrier.

Bis-N-heterocyclic carbene (NHC) aminopincer ligands were successfully applied for the first time in the catalytic hydrogenation of esters. We have isolated and characterized a well-defined catalyst precursor as a dimeric [Ru2(L)2Cl3]PF6 complex and studied its reactivity and catalytic performance. Remarkable initial activities up to 283,000 h(-1) were achieved in the hydrogenation of ethyl hexanoate at only 12.5 ppm Ru loading. A wide range of aliphatic and aromatic esters can be converted with this catalyst to corresponding alcohols in near quantitative yields. The described synthetic protocol makes use of air-stable reagents available in multigram quantities, rendering the bis-NHC ligands an attractive alternative to the conventional phosphine-based systems.

The front cover artwork for Issue 6/2014 is provided by the research group of Inorganic Materials Chemistry and the Institute for Complex Molecular Systems, Eindhoven University of Technology (The Netherlands). The image shows a concept of a hydrogen battery in which H2 storage and its release are achieved through reversible hydrogenation of CO2 catalysed by an Ru‐PNP pincer complex. See the Communication itself at .

Milder, faster, stronger, better! The cover shows a conceptual hydrogen battery in which H2 storage and its release are achieved through reversible catalytic hydrogenation of CO2 with an Ru‐PNP pincer complex. In their Communication on E. A. Pidko et al. describe a homogeneous catalytic system that shows unprecedented activity in both CO2 hydrogenation and dehydrogenation of HCO2H. The authors describe a key role of the base promoter on the reaction mechanism, the overall performance of the system, and its H2 storage capacity.