Development of Nanoalloy Catalysts for Realization of Carbon-Neutral Energy Cycles

Abstract

Increase of CO2 concentration in the atmosphere is one of reasons for the global warming. Development of energy circulation systems, which do not emit CO2 in the atmosphere, is an emergent issue for present-generation scientists [1]. As an answer, we have proposed a new type of energy circulation system, namely, carbon-neutral energy (CN) cycle. With a practical application in mind, three limitations are imposed on the CN cycle; (1) no CO2 emissions, (2) utilization of liquid fuels and (3) minimizing the use of precious metal catalysts. In anticipation of a practical use in the near future, an alkaline fuel cell will be adapted for the CN cycle where non-platinum catalysts can work. For our purpose, electric power will be generated by partial oxidation of alcohols to carboxylic acids.[2] In view of ease in handling, fuels having a high boiling point (b.p.) are favorable for the CN cycles. To this end, glycol (EG) of which b.p. is 470 K an ideal candidate as a fuel. In this case, an oxidized product of EG can be oxalic acid. Compared to the energy obtained by the complete oxidation of EG into CO2, we can derive ca. 80 % of energy even in the partial oxidation of EG to oxalic acid, implying that the EG/oxalic cycle possibly works as an energy cycle. We herein show an example of selective EG oxidation catalysts working in alkaline conditions.