美国俄勒冈州立大学工程学院(Oregon State University College of Engineering)的研究人员与康纳尔大学Cornell University以及美国阿贡国家实验室(Argonne National Laboratory)的研究人员合作，将让利用水高效大规模制氢即将成为现实。

由于俄勒冈州立大学工程学院的研究人员以及康奈尔大学和阿贡国家实验室的合作者们的努力，从水中高效地大量生产氢气离成为现实越来越近。

 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.

科学家们利用先进的实验工具对电化学催化过程有了更清晰的认识，该过程比从天然气中提取氢气更清洁、更可持续。

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.

了解铱酸锶催化剂活性高的原因（图片来源：俄勒冈州立大学）

研究结果今天发表在《科学进展》上。

Findings were published today in Science Advances.

氢气存在于地球上各种各样的化合物中，最常见的是与氧气结合成水，它具有许多科学、工业和能源相关的作用。它还以碳氢化合物的形式出现，碳氢化合物由氢和碳组成，如天然气的主要成分甲烷。

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.

"氢气的生产对我们生活的许多方面都很重要，例如汽车的燃料电池和许多有用的化学品的制造，如氨，"俄勒冈州立大学的Zhenxing Feng说，他是领导这项研究的化学工程教授。"它还用于提炼金属，用于生产人造材料，如塑料和一系列其他用途。"

“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.”

根据能源部的数据，美国的大部分氢气都是通过一种被称为蒸汽-甲烷重整的技术从天然气等甲烷来源中生产出来的。该过程包括在催化剂存在的情况下将甲烷置于加压蒸汽中，产生反应，产生氢气和一氧化碳以及少量二氧化碳。

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.

下一步称为水气转换反应，一氧化碳和蒸汽通过不同的催化剂发生反应，生成二氧化碳和额外的氢气。最后一步，压摆吸附，二氧化碳和其他杂质被去除，留下纯氢。

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.

"与天然气重整相比，利用可再生资源的电力来分水制氢更清洁、更可持续。"冯建国说。"但是，水分裂的效率很低，主要是由于过程中一个关键的半反应--氧进化反应或OER--的高过电位--即电化学反应的实际电位与理论电位之差。"

“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.”

半反应是氧化还原反应或还原-氧化反应中电子在两个反应物之间转移的两个部分之一，还原指获得电子，氧化指失去电子。

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.

半反应的概念常被用来描述电化学电池中的情况，半反应通常被用来作为平衡氧化还原反应的一种方法。过电位是理论电压与引起电解--一种由应用电流驱动的化学反应--所需的实际电压之间的裕度。

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.

"电催化剂对于通过降低过电位来促进分水反应至关重要，但开发高性能的电催化剂远非一蹴而就，"冯说。"主要的障碍之一是缺乏有关电催化剂在电化学操作过程中结构演变的信息。了解电催化剂在电化学操作过程中的结构和化学演变对于开发高质量的电催化剂材料，进而实现能源的可持续发展至关重要。"

“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和合作者使用了一套先进的表征工具，研究了一种最先进的OER电催化剂--铱酸锶（SrIrO3）在酸性电解质中的原子结构演变。

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.

"我们想了解其创纪录的OER高活性的起源--比常见的商业催化剂--氧化铱高1000倍，"冯说。"利用阿贡基于同步加速器的X射线设施和OSU西北纳米技术基础设施站点基于实验室的X射线光电子能谱，我们观察到SrIrO3在OER期间的表面化学和结晶到非晶态的转变。"

“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.”

通过观察，我们深入了解了铱酸锶能够作为催化剂发挥如此好的作用背后所发生的事情。

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

"我们详细的、原子尺度的发现解释了活性铱酸锶层是如何在铱酸锶上形成的，并指出了晶格氧活化和耦合离子扩散对活性OER单元形成的关键作用，"他说。

“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补充说，这项工作提供了关于应用电势如何促进电化学界面上功能性非晶层的形成的见解，并为设计更好的催化剂提供了可能性。

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.

与Feng合作的是化学工程教授Gregory Herman，他领导了俄勒冈州立大学由国家科学基金会资助的西北纳米技术基础设施站点，以及Trey Diulus，他曾是俄勒冈州立大学的博士生，现在是瑞士苏黎世大学的博士后研究员。

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.

此外，来自比利时鲁汶天主教大学、中国科技大学和休斯顿大学的研究人员也为这项研究做出了贡献。

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.

除了美国国家科学基金会，能源部也支持这项研究。

Along with the NSF, the Department of Energy supported this research.