Tokyo Institute of Technology finds new electrocatalyst materials that can be used for hydrogen production with low cost/high efficiency

Fossil fuel is not only a non-renewable energy source, but also one of the main causes of global warming and air pollution.
Therefore, many scientists place their hopes on hydrogen fuel
.
Hydrogen is a clean fuel, and its energy density is very high, but how to efficiently produce a large amount of hydrogen is still an arduous technical challenge
.
? (Image source: Tokyo Institute of Technology)? Water splitting is one of the most commonly used hydrogen production methods
.
In this process, catalysts made of precious metals such as platinum, ruthenium and iridium have excellent performance, but the cost is too high
.
The problem is that in the critical oxygen evolution reaction (OER), if an electrocatalyst made of a rich metal is used, the efficiency is too low
.
According to foreign media reports, scientists at Tokyo Institute of Technology in Japan have discovered an electrocatalyst material-calcium iron oxide (CaFe2O4), which can be water-decomposed and is extremely cost-effective
.
In the OER reaction, iron oxides are mediocre, but previous studies have shown that their performance can be improved to practically usable levels when combined with other metals
.
Researcher Dr.
Yuuki Sugawa said: “We want to reveal the potential of CaFe2O4 and clarify the key factors that promote its OER activity by comparing it with other iron-based bimetallic oxides
.
” The team tested six iron-based oxides for this purpose.
Oxides, including CaFe2O4
.
The results show that the OER performance of CaFe2O4 is much higher than other bimetallic electrocatalysts, and even higher than the commonly used iridium oxide
.
In addition, the test shows that this material has durability, and there is no obvious structure and composition change after the test cycle, and the performance of the CaFe2O4 electrode in the electrochemical cell is still very high
.
? In order to understand the reasons for the excellent performance of this electrocatalyst, scientists used density functional theory to calculate and discovered an unconventional catalytic mechanism
.
This indicates that CaFe2O4 provides an energy-feasible way for the formation of oxygen bonds, which is a restrictive step in OER
.
Although more theoretical calculations and experiments are needed to confirm, the results show that the close distance between multiple iron sites plays a key role
.
? Dr.
Sugawara said? The newly discovered OER electrocatalyst will bring about fundamental changes
.
"CaFe2O4 has many advantages, such as easy synthesis, low cost, and low environmental impact
.
It is expected to be a promising OER electrocatalyst for water splitting, opening up new ways for the development of energy conversion equipment
.
In addition, the new OER found in CaFe2O4 is enhanced The mechanism can be used in the engineering design of other useful catalysts
.
"