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[资源] 瑞典皇家科学院介绍2007年Nobel化学奖得主Gerhard Ertl教授主要成就

Introduction
The Nobel Prize in chemistry for 2007 is awarded to Gerhard Ertl for his thorough
studies of fundamental molecular processes at the gas-solid interface. When a small
molecule hits a solid surface from a gas phase there are a number of possible
outcomes. The molecule may simply either bounce back or be adsorbed. It is the latter
case that carries the most interesting possibilities. The interaction with the atoms of
the surface can be so strong that the molecule dissociates into constituent groups or
atoms. The molecule can also react directly with surface groups and change the
chemical properties of the surface. A third possibility is that the adsorbed molecule
encounters another previously adsorbed one and there is a binary chemical reaction on
the surface.
There are very important practical situations where these scenarios are the key
chemical events. Heterogeneous catalysis has been a central process in the chemical
industry for a century. The agriculture of the world has been supplied with fertilizers
rich in nitrogen since 1913 due to the Haber-Bosch process, where the nitrogen of the
air is converted to ammonia using an iron-based catalyst. Today every car produced
has a catalyst system that converts carbon monoxide and hydrocarbons to carbon
dioxide in the exhaust gases. Also the content of nitrous gases is reduced through the
action of the catalyst. Thin semiconductor layers are produced by chemical vapor
deposition (CVD) in large quantities in the microelectronics industry. Currently large
resources are devoted to the development of efficient fuel cells that would enable the
use of hydrogen as a standard vehicle fuel. Corrosion, which is caused by chemical
reactions at surfaces, is a major problem both in everyday life and in more
sophisticated industrial contexts such as in nuclear power plants and airplanes.
Damage by corrosion may be reduced by adjusting the composition of the surface so
that it is protected by an oxide layer formed in air. It is clear that chemical processes
at surfaces play a central role in wide span of economically highly significant
applications of chemical knowledge to the solution of practical problems.
The study of chemical processes at surfaces also plays a significant role from the
perspective of basic chemical research. In our theoretical description of chemical
reactions the formation of a molecule in the gas phase provides the conceptually most
simple case. Here it is possible to consider a reacting species affected only by the
encounter with the reaction partner. However, in most applications of practical
importance reactions occur in more complex environments, where the reacting species
are constantly exchanging energy and momentum with other neighboring molecules.
In a solution the environment is disordered and dynamic. In the description of such
systems one typically has to rely on considering the effect of the environment through
its average properties. The gas-solid interfaces provide one example of an
environment that is intermediate between the relative simplicity of the gas phase and
the molecular complexity of the liquid phase. At the surface of a solid an adsorbed
molecule can exchange energy and momentum with the support, but in the most ideal
cases the support has long-range order. The consequence is that the interaction
between molecule and support is much more regular, which allows for more precise
experiments and more detailed theoretical descriptions. Thus one can see the study of
chemical reactions on surfaces as one route towards a deeper understanding of
reactions in condensed phases in general.

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