No abstract

n-Butanol is an important industrial chemical usually produced by the oxo process, an expensive, energyconsuming set of reactions over metal catalysts, using petrochemical raw materials at high pressure. We developed nonstoichiometric hydroxyapatite (HAP), a highly active calcium phosphate compound and found it catalyzed selective conversion of ethanol to n-butanol in a single reaction at atmospheric pressure and low temperature, with maximum selectivity of 76%. Higher alcohols were also formed. We postulate that ethanol is adsorbed and activated on HAP as CH 3 CH 2 OH(a) and that a C-C bond was formed between β-C in the CH 3 CH 2 OH(a) and R-C in n-C n H 2n+1 OH to produce n-C n H 2n+1 CH 2 CH 2 OH. We further postulate that, by successive propagation, part of this n-C n H 2n+1 CH 2 CH 2 OH is then adsorbed and activated on HAP as n-C n H 2n+1 CH 2 CH 2 OH(a) and that C-C bond was formed between β-C in the n-C n H 2n+1 CHCH 2 OH(a) and R-C in n-alcohol to produce branched alcohols. Reaction simulation supported this hypothesis, suggesting that efficient, environmentally friendly production of n-butanol might be possible in future using bioethanol as raw material.

No abstract

For the development of a rechargeable metal-air battery, which is expected to become one of the most widely used batteries in the future, slow kinetics of discharging and charging reactions at the air electrode, i.e., oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), respectively, are the most critical problems. Here we report that Ruddlesden-Popper-type layered perovskite, RP-LaSr3Fe3O10 (n = 3), functions as a reversible air electrode catalyst for both ORR and OER at an equilibrium potential of 1.23 V with almost no overpotentials. The function of RP-LaSr3Fe3O10 as an ORR catalyst was confirmed by using an alkaline fuel cell composed of Pd/LaSr3Fe3O10-2x(OH)2x·H2O/RP-LaSr3Fe3O10 as an open circuit voltage (OCV) of 1.23 V was obtained. RP-LaSr3Fe3O10 also catalyzed OER at an equilibrium potential of 1.23 V with almost no overpotentials. Reversible ORR and OER are achieved because of the easily removable oxygen present in RP-LaSr3Fe3O10. Thus, RP-LaSr3Fe3O10 minimizes efficiency losses caused by reactions during charging and discharging at the air electrode and can be considered to be the ORR/OER electrocatalyst for rechargeable metal-air batteries.