William Goddard and Colleagues Awarded Horizon Prize from the Royal Society of Chemistry

William A. Goddard, III (PhD '65), the Charles and Mary Ferkel Professor of Chemistry, Materials Science, and Applied Physics at Caltech, is part of a team that is being honored with the 2024 Faraday Horizon Prize from the Royal Society of Chemistry (RSC), a prize that recognizes "significant recent novel discoveries or advances made in the area of physical chemistry."

The team, led by Xiangfeng Duan, professor of chemistry and biochemistry at UCLA, is being honored for its decade-long research program that developed a technique called electrical transport spectroscopy (ETS), which makes it possible to study the surface chemistry of electrochemical interfaces even at the nanoscale. Specifically, the team used ETS to experimentally determine the acidity of hydronium (H₃O⁺) at the surface of a platinum nanowire as well as its role in pH-dependent hydrogen evolution reactions.

In a written statement, the RSC wrote, "The team have made a breakthrough in understanding how water interacts with the surface of platinum, which is crucial for clean energy technologies like hydrogen fuel cells. They have invented a new method to directly probe the water structure at the platinum surface, examine how the hydrogen atoms within it are arranged (protonation status), and how these factors influence the chemical reactions that occur on the platinum."

It is difficult to study such electrochemical interfaces with standard spectroscopic techniques because they occur between a solid electrode and a liquid electrolyte. But an understanding of those interfaces and how they affect the rate of electrocatalytic reactions is important for developing future electrocatalysts, especially for energy applications such as fuel cell technology.

The team's research "revealed that the acidity (pKa) of water next to the platinum is much higher than normal, which helps explain a long-standing puzzle about how the pH of different solutions affects hydrogen production on these surfaces," the RSC statement said.

"This collaboration with Professor Duan of UCLA involving ingenious experiments that can measure the number of protonated waters at the surface of a tiny nanowire just 2 nanometers wide stimulated us to extend one of our quantum mechanical methods to be capable of describing the distribution of hydronium ions near the surface of this nanowire," explains Goddard. "The results agree well with the surface concentration, while also showing that the concentration decays just a few nanometers from the nanowire surface."

Goddard earned his doctoral degree from Caltech in 1965. He was a Noyes research fellow in chemistry from 1964 to 1966 and a Noyes research instructor in 1966. He became an assistant professor of theoretical chemistry in 1967, an associate professor in 1971, and a full professor in 1974. He was named professor of chemistry and applied physics in 1978, the Ferkel Professor of Chemistry in 1984, and Ferkel Professor of Chemistry, Materials Science, and Applied Physics in 2001.

Of the award, Goddard says, "I am elated at the news and shared it with my four children, 14 grandchildren, and five great-grandchildren (not sure the great-grandchildren understood)."

In addition to Goddard and Duan, awardees on the project include former Caltech postdoctoral scholar Tao Cheng, now a professor at Soochow University in China, and UCLA colleagues Anastassia N. Alexandrova, Hung-Chieh Cheng, Mengning Ding, Qiyuan He, Yu Huang, Zhihong Huang, Tianle Leng, Aamir Hassan Shah, Chengzhang Wan, Gongming Wang, Sibo Wang, Zisheng Zhang, and Guangyan Zhong.