We accomplished efficient electrocatalytic low-temperature ammonia synthesis with the highest yield reported to date.

No abstract

Low-temperature heterogeneous catalytic reaction in an electric field is anticipated as a novel approach for on-demand and small-scale catalytic processes.

The catalytic conversion of sugars to lactic acid esters holds great advantages over the conventional fermentation process; the reaction is faster and the product can be separated with a simple distillation process. As the conversion of the sugar to the lactic acid ester involves several elemental reactions, multi-component catalyst systems were expected to be effective for this reaction. This paper reports the use of a combination of indium chloride and tin chloride to synergistically catalyze the formation of methyl lactate (MeLac) from sugars in the presence of tetrafluoroborate salts, the maximum yield of which reaches 72 %. A plausible reaction scheme is also proposed based on the electrospray ionization mass spectroscopy analyses of the reaction solutions and the effects of the indium species, tin species, and tetrafluoroborate salts on each elemental step from fructose to MeLac.

Efficient ammonia synthesis at low temperatures is anticipated for establishing a hydrogen carrier system. We reported earlier that application of an electric field on the Cs/Ru/SrZrO3 catalyst enhanced catalytic ammonia synthesis activity. It is now clear that N2 dissociation is activated by hopping protons in the electric field. Efficient ammonia synthesis proceeds by an “associative mechanism” in which N2 dissociates via an N2H intermediate, even at low temperatures. The governing factor of ammonia synthesis activity in an electric field for active metals differed from that in the conventional mechanism. Also, N2H formation energy played an important role. The effects of dopants (Al, Y, Ba, and Ca) on this mechanism were investigated using activity tests and density functional theory calculations to gain insights into the support role in the electric field. Ba and Ca addition showed positive effects on N2H formation energy, leading to high ammonia synthesis activity. The coexistence of proton-donating and electron-donating abilities is necessary for efficient N2H formation at the Ru–support interface.