Gerhard Ertl

Gerhard Ertl
Ertl in 2007
Gerhard Ertl
Born	10 10, 1936
Birthplace	Stuttgart-Bad Cannstatt, Baden-Württemberg, Germany
Nationality	German
Occupation	Physicist, surface chemist
Title	Professor emeritus
Employer	Fritz-Haber-Institut der Max-Planck-Gesellschaft
Known for	Surface chemistry, catalysis on solid surfaces
Education	Technical University of Munich (Ph.D.)
Awards	Nobel Prize in Chemistry (2007), Wolf Prize in Chemistry (1998), Japan Prize (1992)
Website	[http://www.fhi-berlin.mpg.de/pc/ertl/welcome.html Official site]

Gerhard Ertl (born 10 October 1936) is a German physicist and surface chemist who serves as Professor emeritus at the Department of Physical Chemistry of the Fritz-Haber-Institut der Max-Planck-Gesellschaft in Berlin, Germany. Over a career spanning more than four decades, Ertl developed the experimental and theoretical foundations of modern surface chemistry — the study of chemical processes that occur on the surfaces of solid materials. His meticulous work illuminated the molecular-level mechanisms by which catalytic converters clean automobile exhaust, how fuel cells generate energy without pollution, and even why iron rusts. In 2007, on his 71st birthday, Ertl was awarded the Nobel Prize in Chemistry for his studies of chemical processes on solid surfaces, a recognition that cemented his standing as one of the most consequential physical chemists of his generation. His research has had far-reaching implications not only for industrial catalysis but also for environmental science, including the understanding of ozone layer destruction in the stratosphere.

Early Life

Gerhard Ertl was born on 10 October 1936 in Stuttgart-Bad Cannstatt, a district of Stuttgart in the state of Baden-Württemberg, Germany. He grew up in post-war Germany during a period of significant reconstruction and social transformation. Stuttgart, an industrial city in southwestern Germany known for its engineering traditions, provided an environment that may have influenced his early interest in the physical sciences. Little detailed information about his family background and childhood has been published in public sources, but Ertl's subsequent educational trajectory through major German research universities reflects a deep engagement with physics and chemistry from an early age.

Germany's post-war scientific community was in a period of rebuilding during Ertl's formative years, and the country's universities were re-establishing themselves as centers of research excellence. The tradition of German physical chemistry, which had produced luminaries such as Fritz Haber — the namesake of the institute where Ertl would spend much of his career — provided an intellectual heritage that shaped the direction of Ertl's scientific pursno inquiry. His early exposure to the physical sciences set the stage for a career that would fundamentally transform the understanding of chemical reactions at surfaces.

Education

Ertl pursued his higher education at two of Germany's leading technical universities. He studied at the University of Stuttgart, where he received his initial training in physics and chemistry. He subsequently moved to the Technical University of Munich (Technische Universität München), where he completed his doctoral studies under the supervision of Heinz Gerischer, a distinguished electrochemist known for his contributions to semiconductor electrochemistry and surface science. Gerischer's influence was significant in directing Ertl's attention toward the physical chemistry of surfaces and interfaces, a field that would become Ertl's life's work. The combination of rigorous training at both Stuttgart and Munich equipped Ertl with the experimental skills and theoretical grounding necessary to tackle the complex problems of surface chemistry that had long eluded definitive molecular-level explanation.

Career

Development of Surface Chemistry Methods

Ertl's career was dedicated to understanding the fundamental processes that occur when molecules interact with solid surfaces. This area of research, known as surface chemistry, is central to numerous industrial processes and natural phenomena, yet for much of the twentieth century it remained poorly understood at the molecular level. The difficulty lay in the complexity of surfaces themselves: unlike bulk materials, surfaces represent a boundary where the orderly arrangement of atoms is disrupted, creating unique chemical environments.

Ertl developed and refined a suite of experimental techniques that allowed researchers to study these surface processes with unprecedented precision. His approach combined methods from various branches of physics and chemistry, enabling the observation of individual steps in surface reactions. As the Nobel Prize citation noted, Ertl "provided a detailed description of how chemical reactions take place on surfaces," work that applied "in both academic studies and industrial development."

In his Nobel Lecture, published in 2008, Ertl described how advances in experimental techniques made it possible to investigate reactions at surfaces "from atoms to complexity." He discussed how the spatio-temporal formation of patterns on surfaces during chemical reactions could be understood and modeled, representing a major advance in the field.

The Haber-Bosch Process

One of Ertl's most significant contributions was his elucidation of the surface chemistry underlying the Haber-Bosch process, the industrial method for synthesizing ammonia from nitrogen and hydrogen gases. This process, developed in the early twentieth century by Fritz Haber and Carl Bosch, is one of the most important chemical reactions in human history, as it enables the production of fertilizers that support global food production. Despite its immense practical importance, the detailed molecular mechanism by which nitrogen molecules are broken apart and combined with hydrogen on the surface of an iron catalyst had not been fully understood before Ertl's work.

Ertl's research provided a step-by-step description of how nitrogen and hydrogen molecules adsorb onto the iron catalyst surface, how the strong triple bond of the nitrogen molecule is broken, and how the resulting nitrogen atoms combine with hydrogen atoms to form ammonia. This work was not merely of academic interest; it offered insights that could potentially be used to improve the efficiency of one of the world's most energy-intensive industrial processes.

Catalytic Oxidation of Carbon Monoxide

Another major area of Ertl's research concerned the catalytic oxidation of carbon monoxide on platinum surfaces, a reaction of central importance to the operation of catalytic converters in automobiles. By studying this reaction in detail, Ertl was able to describe the mechanism by which toxic carbon monoxide is converted to carbon dioxide on the surface of the platinum catalyst. This work had direct relevance to efforts to reduce air pollution from vehicle emissions.

Ertl's investigations of this reaction also revealed fascinating examples of nonlinear dynamics on surfaces. His research on oscillatory kinetics and spatio-temporal self-organization in reactions at solid surfaces demonstrated that chemical reactions far from equilibrium on solid surfaces could exhibit the typical phenomena of nonlinear dynamics. He showed, for example, that the catalytic oxidation of carbon monoxide could produce oscillating reaction rates and intricate spatial patterns on the catalyst surface. These findings connected surface chemistry to the broader field of complexity science and nonlinear dynamics, demonstrating that even seemingly simple catalytic reactions could give rise to emergent, self-organizing behavior.

Environmental Implications

Ertl's work extended beyond industrial catalysis to address questions of environmental significance. The Royal Swedish Academy of Sciences noted in the Nobel Prize citation that "surface chemistry can even explain the destruction of the ozone layer, as vital steps in the reaction actually take place on the surfaces of small crystals of ice in the stratosphere." This observation highlighted the breadth of Ertl's contributions: his fundamental research on how molecules interact with surfaces provided a framework for understanding not only industrial processes but also atmospheric chemistry and environmental degradation.

The connection between surface chemistry and ozone depletion relates to the role that ice crystal surfaces in polar stratospheric clouds play in facilitating the chemical reactions that release chlorine and bromine atoms, which then catalyze the destruction of ozone molecules. Ertl's methods for studying surface reactions helped elucidate these processes at the molecular level, contributing to the scientific understanding that underpinned international efforts to protect the ozone layer.

Fuel Cell Research

Ertl's research also had implications for the development of fuel cells, which generate electricity through electrochemical reactions at electrode surfaces. Astrid Graslund, secretary of the Nobel Committee for Chemistry, stated that Ertl's work "paved the way for development of cleaner energy sources and will guide the development of fuel cells." By providing detailed molecular-level understanding of how chemical reactions proceed at surfaces, Ertl's work offered insights that could be applied to improving the efficiency and reducing the cost of fuel cell technology, a key component of efforts to transition to cleaner energy systems.

Fritz-Haber-Institut der Max-Planck-Gesellschaft

For much of his career, Ertl was based at the Fritz-Haber-Institut der Max-Planck-Gesellschaft in Berlin, one of Germany's premier research institutions for physical chemistry and chemical physics. As director of the Department of Physical Chemistry at the institute, he built a research group that became one of the world's leading centers for surface science. The institute, named after Fritz Haber, the Nobel Prize-winning chemist who developed the ammonia synthesis process, provided a fitting intellectual home for Ertl's work on the surface chemistry of catalysis.

Following his formal retirement, Ertl continued his association with the institute as Professor emeritus, maintaining his connection to the research community and the institution that had been central to his scientific career. A lecture award bearing his name, the Gerhard Ertl Lecture Award, was established to honor outstanding contributions to surface chemistry and catalysis. In 2021, the 14th Gerhard Ertl Lecture Award was given to Omar M. Yaghi, Professor of Chemistry at the University of California, Berkeley.

Mentorship

In addition to his own research, Ertl supervised numerous doctoral students and postdoctoral researchers who went on to make significant contributions to surface science and related fields. Among his doctoral students was Martin Wolf, who continued to advance the field of surface dynamics and ultrafast spectroscopy. Through his mentorship, Ertl helped train a generation of surface scientists who carried forward the methods and intellectual traditions he had established.

Personal Life

Gerhard Ertl has been described as a modest and thoughtful scientist. In an interview conducted on 6 December 2007, shortly after receiving the Nobel Prize, Ertl discussed his career and scientific philosophy with Adam Smith, Editor-in-Chief of Nobelprize.org. The fact that his Nobel Prize was announced on his 71st birthday — 10 October 2007 — added a personal dimension to the celebration that was widely noted in media coverage.

In 2015, Ertl demonstrated his concern for environmental issues by signing the Mainau Declaration 2015 on Climate Change on the final day of the 65th Lindau Nobel Laureate Meeting. The declaration, signed by a total of 76 Nobel Laureates, was presented to François Hollande, then President of the French Republic, as part of the COP21 climate summit in Paris. This action reflected the intersection of Ertl's scientific expertise in surface chemistry — including its relevance to atmospheric chemistry and clean energy — with broader concerns about climate change and environmental sustainability.

In an interview published by the German magazine Cicero, Ertl discussed questions relating to science and belief, providing a glimpse into his intellectual life beyond the laboratory.

Recognition

Nobel Prize in Chemistry (2007)

The most prominent recognition of Ertl's career came on 10 October 2007, when the Royal Swedish Academy of Sciences announced that he had been awarded the Nobel Prize in Chemistry "for his studies of chemical processes on solid surfaces." The announcement came on Ertl's 71st birthday, a coincidence that was widely reported in the press. The Nobel committee emphasized that Ertl's research had laid the foundation for modern surface chemistry, providing detailed molecular-level descriptions of how chemical reactions take place on surfaces. The committee noted applications ranging from industrial catalysis to the understanding of ozone layer destruction.

In its speed read summary of the prize, the Nobel organization compared productive chemical reactions to a successful dinner party, noting that "productive chemical reactions depend upon getting the right components to mingle in the right surroundings, and often" a surface provides the critical environment for such interactions.

Wolf Prize in Chemistry (1998)

Prior to the Nobel Prize, Ertl received the Wolf Prize in Chemistry in 1998, one of the most prestigious awards in the chemical sciences. The Wolf Prize, awarded by the Wolf Foundation in Israel, recognizes outstanding achievements in science and the arts. Ertl's receipt of this prize reflected the international recognition of his contributions to surface chemistry well before the Nobel award.

Japan Prize (1992)

In 1992, Ertl was awarded the Japan Prize, an international award presented by the Japan Prize Foundation to individuals who have made significant contributions to science and technology. This early recognition of Ertl's work signaled his growing international stature in the field of surface science.

Gerhard Ertl Lecture Award

A lecture award was established in Ertl's name to honor outstanding contributions to the field of surface chemistry and related disciplines. The Gerhard Ertl Lecture Award has been given annually to researchers who have made exceptional advances in the field. The 14th recipient, in 2021, was Omar M. Yaghi of the University of California, Berkeley, recognized for his work in reticular chemistry.

Legacy

Gerhard Ertl's contributions to surface chemistry represent a transformation of the field from a largely empirical discipline into one grounded in detailed molecular-level understanding. Before Ertl's work, the interactions between molecules and solid surfaces were understood primarily through macroscopic observations and phenomenological models. Ertl developed the experimental methodology — combining techniques such as low-energy electron diffraction, X-ray photoelectron spectroscopy, and scanning tunneling microscopy — to observe and characterize the individual steps of surface reactions with atomic-level precision.

The practical implications of Ertl's research are extensive. His elucidation of the Haber-Bosch process contributed to the understanding of one of the most important industrial chemical reactions in history. His work on catalytic oxidation of carbon monoxide on platinum surfaces informed the development of catalytic converters that reduce air pollution from vehicles. And his research on oscillatory kinetics demonstrated the connections between surface chemistry and the broader field of nonlinear dynamics and complexity science.

The environmental relevance of Ertl's work has become increasingly appreciated over time. His demonstration that surface chemistry plays a role in ozone depletion provided molecular-level insight into one of the most pressing environmental issues of the late twentieth century. Similarly, his contributions to the understanding of fuel cell chemistry have relevance to ongoing efforts to develop clean energy technologies.

Through his training of doctoral students and postdoctoral researchers, Ertl established a scientific lineage that continues to advance the field. The Gerhard Ertl Lecture Award serves as a further testament to his enduring influence, providing ongoing recognition for excellence in surface chemistry. His signing of the Mainau Declaration on Climate Change in 2015, alongside 75 other Nobel Laureates, demonstrated his commitment to applying scientific knowledge to address global challenges.

Ertl's career exemplifies the deep connections between fundamental research and practical application. By pursuing a rigorous, curiosity-driven investigation of how molecules behave at surfaces, he generated knowledge that proved essential for understanding and improving technologies ranging from fertilizer production to pollution control to clean energy generation. His work remains a cornerstone of modern physical chemistry and surface science.