Mass transport enhancement effect induced by superstructure catalyst for carbon dioxide reduction to formic acid

The CO 2 electrochemical reduction reaction (CO 2 ERR) offers an effective way to solve the problems of energy storage fluctuation and CO 2 over-emission at the same time. However, the mass transfer limitation during CO 2 ERR owing to the gaseous property of CO 2 greatly restricts the efficiency and selectivity of CO 2 reduction. Here, we report, for the first time, the design of a copper-zinc (CuZn) bimetal decorated superstructure catalyst (CuZn@KCA) via capitalizing on porous N-doped konjac glucomannan (KGM) aerogel and CuZn metal organic frameworks (CuZn-MOF), based on multiphysics infinite elemental simulations. The CuZn@KCA catalysts show high performance for CO 2 ERR (faradaic efficiency for HCOOH reaches 75% at −1.0 V vs. RHE). As demonstrated by infinite elemental simulations and detailed characterizations, the improved CO 2 ERR is attributed to the mass transfer enhancement effect of the superstructure catalyst on the reaction process (The mass transfer with CuZn@KCA is 16 times higher than that with CuZn-MOF). As such, the strategy for crafting a hierarchical superstructure might open up an avenue to improve the reaction activity of CO 2 ERR.