Solaris providing an additional 12 Urbino electric buses to Cluj Napoca
Momentum Dynamics to deliver 200 kW wireless charging systems for Martha's Vineyard Transit Buses

Univ of Illinois team mixed metals with perchloric acid to create stable, efficient catalyst for water splitting

Researchers from the University of Illinois at Urbana-Champaign have metal compounds with perchloric acid to create a stable, efficient electrocatalytic material for the oxygen evolution reaction in acidic media.

The resulting porous Y2[Ru1.6Y0.4]O7−δ electrocatalyst exhibits a turnover frequency (TOF) of 560 s−1 (at 1.5 V versus RHE) for the oxygen evolution reaction—two orders of magnitude higher than that of the RuO2 reference catalyst (5.41 s−1). A paper on their work is published in the journal Angewandte Chemie.

Electrolyzers use electricity to break water molecules into oxygen and hydrogen. The most efficient of these devices use corrosive acids and electrode materials made of the metal compounds iridium oxide or ruthenium oxide. Iridium oxide is the more stable of the two, but iridium is one of the least abundant elements on Earth, so researchers are in search of an alternative material.

Much of the previous work was performed with electrolyzers made from just two elements—one metal and oxygen. In a recent study, we found if a compound has two metal elements—yttrium and ruthenium—-and oxygen, the rate of water-splitting reaction increased.

—Hong Yang, a co-author and professor of chemical and biomolecular engineering at Illinois

Yao Qin, a co-author and former member of Yang’s group, first experimented with the procedure for making this new material by using different acids and heating temperatures to increase the rate of the water-splitting reaction.

The researchers found that when they used perchloric acid as a catalyst and let the mixture react under heat, the physical nature of the yttrium ruthenate product changed.

The material became more porous and also had a new crystalline structure, different from all the solid catalysts we made before.

—Jaemin Kim, the lead author and a postdoctoral researcher

The superior activity results from both high surface area of the porous structures and the optimized energy band structure due to the oxygen lattice defects, which arise from the mixed oxidation state of Ru4+/5+ due to the partial substitution by Y3+ on the B-site. This work shows a new synthetic strategy for making high-temperature stable porous metal oxides and a valuable approach to the design of electrocatalysts.

—Kim et al.

Yang and his team looked at the structure of their new material with an electron microscope and found that it is four times more porous than the original yttrium ruthenate they developed in a previous study, and three times that of the iridium and ruthenium oxides used commercially.

It was surprising to find that the acid we chose as a catalyst for this reaction turned out to improve the structure of the material used for the electrodes. This realization was fortuitous and quite valuable for us.

—Jaemin Kim

The next steps for the group are to fabricate a laboratory-scale device for further testing and to continue to improve the porous electrode stability in acidic environments, Yang said.

Resources

  • Jaemin Kim, Pei‐Chieh Shih, Yao Qin, Zaid Al‐Bardan, Cheng‐Jun Sun, Hong Yang (2018) “A Porous Pyrochlore Y2[Ru1.6Y0.4]O7–δ Electrocatalyst for Enhanced Performance towards the Oxygen Evolution Reaction in Acidic Media” Angewandte Chemie doi:

Comments

HarveyD

This could be one of the 101 ways to split water and extract affordable clean H2 for industrial usage and FCEVs?

D

I have been waiting a long time for a cheap clean way to split water. So many disappointments to date and it looks like it will be a long time before this is done as well.

Verify your Comment

Previewing your Comment

This is only a preview. Your comment has not yet been posted.

Your comment could not be posted. Error type:
Your comment has been posted. Post another comment

The letters and numbers you entered did not match the image. Please try again.

As a final step before posting your comment, enter the letters and numbers you see in the image below. This prevents automated programs from posting comments.

Having trouble reading this image? View an alternate.

Post a comment

Your Information

(Name is required. Email address will not be displayed with the comment.)