Sustainability, in all its aspects, forms the grand challenge of the 21st century. The world is facing an unprecedented economic crisis, together with rising issues concerning the depletion of natural resources and the increasing global pressure on the environment. There are thus diverging, instead of converging, forces acting on the three components of sustainability: economy, society, and environment. An extraordinary effort is required during the coming years to inverse this direction and develop a path that leads towards meeting the needs of the present generation without compromising those of future generations. Efficiency, in the use of energy and resources, is clearly the keyword for going in this direction, meaning better industrial processes with, ideally, zero impact on the environment; clean and renewable energy together with a drastic reduction of energy losses; and improved and better recyclable materials with a drastic reduction of their impact on the environment during their life cycle. These topics coincide with the main scientific domains of ChemSusChem, and in fact sustainable chemistry (or better, sustainability through chemistry) is at the heart of the vision of reaching a sustainable development.
From a general perspective, efficiency means the possibility to maintain our lifestyle and preserve the ecobalance in a world in which an increasing number of people has access to all resources. Unsurprisingly, innovation should be closely linked with the concept of efficiency because both are driving forces for competiveness, particularly in the area of chemistry and energy where the global scenario is changing rapidly and the old macroeconomical approaches are no longer paying off. Thus, it is proposed that efficiency indices replace the gross domestic product (GDP) index, because they better define the level of development of a given country. It is also evident that increased innovation is the only option to preserve economy and job security, and invert the actual trend of an irreversible degradation of the ecosystem.
Among the various interdisciplinary scientific areas, catalysis is a core component in implementing the concepts of efficiency and innovation into industry. After a period at the end of the 20th century, where catalysis and chemistry were considered to have become mature technologies, the central issues of energy and sustainability have greatly pushed the need for better catalysts and new catalytic approaches. Hence, the interest in catalysis as a basic science has been considerably renewed, and there is no doubt that catalysis will be one of the key technologies for allowing sustainable growth in the future. However, the new demanding issues also require fostering new approaches to catalysis, based on interdisciplinarity (from surface science and theory/modeling to applied catalysis and reaction engineering) and integration of competences between the different fields of catalysis (homogeneous catalysis, heterogeneous catalysis, and biocatalysis).
This issue of ChemSusChem is dedicated to presenting some examples that evidence this close link between catalysis, sustainable development, and innovation. The contributions cover various aspects of modern catalysis research. The role of catalysis in chemical process intensification and innovation is discussed in a Minireview article on cascade reactions using solid catalysts (Avelino Corma et al.) and a Review on catalytic oxidation (Fabrizio Cavani and Joaquim Teles). The contributions by Jiří Čejka et al. (palladium catalysts supported on mesoporous molecular sieves for CC bond reactions), Dieter Vogt et al. (heterogeneized homogeneous Pd complexes for allylic alkylation and amination), Matthias Beller et al. (Ru complexes for the selective monoamination of vicinal diols), Lutz Ackermann et al. (Ru complexes for direct arylation reactions), and Pierre Dixneuf et al. (synthesis of bifunctional aldehydes via self- and cross-metathesis) evidence other specific aspects that bridge homogeneous and heterogeneous catalysis.
Different aspects of the sustainable development of specific industrial processes with respect to resources, wastes, hazards, and costs are discussed in detail in the contribution by Jean-Paul Lange. Here, three manufacturing processes are used as examples, namely Shell′s OMEGA, SMPO, and “low monol” technologies for producing ethene diol, styrene/propene oxide, and polyether polyols. Moreover, James Dumesic et al. discuss the catalytic processing of lactic acid, a relevant platform molecule for a potential biorefinery industry. The esterification of acidic oils over solid catalysts is discussed in the Communication by Nicoletta Ravasio et al. With respect to energy, the use of solar energy for the production of hydrogen is discussed in the Review of Josè L. Fierro.
The use of gold-based catalysts for developing new sustainable processes is the third area of this issue, with two contributions: one by Graham Hutchings et al. on the direct synthesis of H2O2 and one by Tamao Ishida and Masatake Haruta on the N-formylation of amines via aerobic oxidation of methanol.
Obviously, these examples cover only a small part of the many contributions of catalysis to the development of new innovative and sustainable chemical processes, and we wish to personally acknowledge the many groups that, despite working on the same topics as covered by this Special Issue, are not directly represented. Further contributions will be presented in the next issues, and we warmly invite all researchers in this field to send their contributions to ChemSusChem, bringing the areas of catalysis and sustainable development closer together.
Matthias Beller and Gabriele Centi Rostock, Germany and Messina, Italy, May 2009.