Key Step Toward Cleaner, More Efficient Mass-Production of Hydrogen From Water

Producing Hydrogen From Water

The lead groups from Cornell University, Oregon State University, and Argonne National Laboratory employ a set of advanced characterization tools to study the atomic structure evolution of a state-of-the-art OER electrocatalyst, strontium iridate (SrIrO3), in acid electrolyte, to understand the origin of its record-high activity (1000 times higher than the commercial catalyst, iridium oxide) for the OER. Credit: Zhenxing Feng, Oregon State University

Efficiently mass-producing hydrogen from water is closer to becoming a reality thanks to Oregon State University College of Engineering researchers and collaborators at Cornell University and the Argonne National Laboratory.

The scientists used advanced experimental tools to forge a clearer understanding of an electrochemical catalytic process that’s cleaner and more sustainable than deriving hydrogen from natural gas.

Findings were published on January 8, 2021, in Science Advances.

Hydrogen is found in a wide range of compounds on Earth, most commonly combining with oxygen to make water, and it has many scientific, industrial and energy-related roles. It also occurs in the form of hydrocarbons, compounds consisting of hydrogen and carbon such as methane, the primary component of natural gas.

“The production of hydrogen is important for many aspects of our life, such as fuel cells for cars and the manufacture of many useful chemicals such as ammonia,” said Oregon State’s Zhenxing Feng, a chemical engineering professor who led the study. “It’s also used in the refining of metals, for producing man-made materials such as plastics, and for a range of other purposes.”

According to the Department of Energy, the United States produces most of its hydrogen from a methane source such as natural gas via a technique known as steam-methane reforming. The process involves subjecting methane to pressurized steam in the presence of a catalyst, creating a reaction that produces hydrogen and carbon monoxide, as well as a small amount of carbon dioxide.

The next step is referred to as the water-gas shift reaction in which the carbon monoxide and steam are reacted via a different catalyst, making carbon dioxide and additional hydrogen. In the last step, pressure-swing adsorption, carbon dioxide, and other impurities are removed, leaving behind pure hydrogen.

“Compared to natural gas reforming, the use of electricity from renewable sources to split water for hydrogen is cleaner and more sustainable,” Feng said. “However, the efficiency of water-splitting is low, mainly due to the high overpotential – the difference between the actual potential and the theoretical potential of an electrochemical reaction – of one key half-reaction in the process, the oxygen evolution reaction or OER.”

A half-reaction is either of the two parts of a redox, or reduction-oxidation, reaction in which electrons are transferred between two reactants; reduction refers to gaining electrons, oxidation means losing electrons.

The concept of half-reactions is often used to describe what goes on in an electrochemical cell, and half-reactions are commonly used as a way to balance redox reactions. Overpotential is the margin between the theoretical voltage and the actual voltage necessary to cause electrolysis – a chemical reaction driven by the application of electric current.

“Electrocatalysts are critical to promoting the water-splitting reaction by lowering the overpotential, but developing high-performance electrocatalysts is far from straightforward,” Feng said. “One of the major hurdles is the lack of information regarding the evolving structure of the electrocatalysts during the electrochemical operations. Understanding the structural and chemical evolution of the electrocatalyst during the OER is essential to developing high-quality electrocatalyst materials and, in turn, energy sustainability.”

Feng and collaborators used a set of advanced characterization tools to study the atomic structural evolution of a state-of-the-art OER electrocatalyst, strontium iridate (SrIrO3), in acid electrolyte.

“We wanted to understand the origin of its record-high activity for the OER – 1,000 times higher than the common commercial catalyst, iridium oxide,” Feng said. “Using synchrotron-based X-ray facilities at Argonne and lab-based X-ray photoelectron spectroscopy at the Northwest Nanotechnology Infrastructure site at OSU, we observed the surface chemical and crystalline-to-amorphous transformation of SrIrO3 during the OER.”

The observations led to a deep understanding of what was going on behind strontium iridate’s ability to work so well as a catalyst.

“Our detailed, atomic-scale finding explains how the active strontium iridate layer forms on strontium iridate and points to the critical role of the lattice oxygen activation and coupled ionic diffusion on the formation of the active OER units,” he said.

Feng added that the work provides insight into how applied potential facilitates the formation of the functional amorphous layers at the electrochemical interface and leads to possibilities for the design of better catalysts.

Reference: “Amorphization mechanism of SrIrO3 electrocatalyst: How oxygen redox initiates ionic diffusion and structural reorganization” by Gang Wan, John W. Freeland, Jan Kloppenburg, Guido Petretto, Jocienne N. Nelson, Ding-Yuan Kuo, Cheng-Jun Sun, Jianguo Wen, J. Trey Diulus, Gregory S. Herman, Yongqi Dong, Ronghui Kou, Jingying Sun, Shuo Chen, Kyle M. Shen, Darrell G. Schlom, Gian-Marco Rignanese, Geoffroy Hautier, Dillon D. Fong, Zhenxing Feng, Hua Zhou and Jin Suntivich, 8 January 2021, Science Advances.
DOI: 10.1126/sciadv.abc7323

Collaborating with Feng were chemical engineering professor Gregory Herman, who leads the National Science Foundation-funded Northwest Nanotechnology Infrastructure site at Oregon State, and Trey Diulus, a former Ph.D. student at OSU and now a postdoctoral researcher at the University of Zurich in Switzerland.

Also contributing to the study were researchers from Université Catholique de Louvain in Belgium, the University of Science and Technology of China and the University of Houston.

6 Comments on "Key Step Toward Cleaner, More Efficient Mass-Production of Hydrogen From Water"

  1. If you rip apart water molecules to create hydrogen you will eventually deplete the planets water.

    • Existing industrial processes currently use about 7 x 10^7 tonnes of hydrogen annually. There are 1.35 x 10^18 metric tonnes of water on Earth and about 2.5% is freshwater. And if you burn the hydrogen or run it through a fuel cell, it returns to water vapor, which falls as rain.

      Of all the reasons to be suspicious of hydrogen hype, running out of water is a very minor one.

    • If you burn the hydrogen or run it through a fuel cell, it returns to water. Ultra-pure water. The purest water you can ever find. This can help our drinking water problems as well as provide power in remote areas.

      Add 5% hydrogen (as measured in BTUs) to ANY existing fuel in your spark-fired or diesel-compression-fired motor, and all the fuel will burn completely in the motor cylinder (in fact, you can burn diesel fuel, low-grade veggie oil, anything, in your spark-fired motor if you add the 5% hydrogen). All particulate emissions will be eliminated: no need for catalytic converters of DEF systems; in fact the air will come out the tailpipe CLEANER than it went in, as all particulates that are already in the air (from plant-based allergens to industrial factory pollution) will be burned also.

      This is all old tech from the 1960s. The University of Arizona studied it alot.

      But the world is controlled by banks. Banks get their power because all oil in the world is sold in U.S. dollars. Countries can be “sanctioned” because they need oil, and oil is sold in one currency only. If you want that oil, gotta play nice with the banks. If oil goes away, banks loose their global control.

  2. “Findings were published on January 8, 2021, in Science Advances.”

    Hmmmm…this site is apparently precognitive. Impressive.

  3. I agree, if humans mesh up with natures’ water composition, sooner or later, that water will not have the efficacy to sustain living things here on earth. What I foresee is doomsday scenario. So please, leave water alone. Clean water is scarce enough. Please do not break it.

  4. Antonio Martins | February 2, 2021 at 10:27 am | Reply

    Rossi Simon simply don’t know about the amount of water on Earth, 72% of its surface! And on use of hydrogen as a fuel the water returns to where it came from!

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