The plastic products around us are synthesized from petroleum, and catalysts play an important role in this process. Catalysts control the rate of reactions, making plastic manufacturing economically feasible, and advances in catalyst technology can contribute to environmental protection and sustainable development.
Plastic products are all around us: the PET bottle you drank this morning, the polyethylene clothes and shoes you’re wearing, the ballpoint pen you’re using, your cell phone, your computer, and so on. In fact, we take plastic so much for granted that we often forget how deeply it is intertwined with our daily lives. Without plastic, we wouldn’t be able to live the convenient lives we do today. Surprisingly, this ubiquitous material was only synthesized from petroleum a few decades ago. Synthesizing plastics involves breaking and lengthening the chemical bonds of reacting substances, and because the bond energy between the atoms that make up a substance is so strong, it would seem that manufacturing plastics made from polymers with hundreds of bonds would require high-temperature conditions of hundreds of degrees. The production process of plastics seems complex, but advances in the technology have allowed us to manufacture plastics in a wide variety of shapes and applications. As a result, it’s no exaggeration to say that modern society is a plastic civilization, and plastic has become an integral part of our lives.
If plastics were manufactured under these harsh conditions, they would be too expensive to be used in everyday products. This is where catalysts come in, to mildly change the conditions. A catalyst is a substance that speeds up or slows down the reaction rate of a chemical phenomenon while maintaining the same state before and after the reaction. Catalysts are indispensable in chemical reactions, and their importance has been emphasized in many industries, not just in today’s plastics production.
Everyday phrases such as “this policy is a catalyst for economic stability for the people” explain how catalysts work. In a chemical reaction, a substance must cross a certain amount of energy barrier to go from one state to another, and this energy barrier is increased or decreased by binding to a catalyst. In general, catalysts are electrocatalysts that lower this energy barrier and speed up the reaction. The lower the energy barrier, the easier it is for the reaction to occur with less energy. It’s like going through a tunnel to get to a region on the other side of a high mountain. On the other hand, if you add a substance that increases this energy barrier, it will slow down the reaction, which is called a co-catalyst. Catalysts are used to slow down exothermic reactions, in which the ambient temperature rises too quickly, or gaseous reactions, in which there is a risk of explosion, in order to make the reaction useful and safe to use.
The importance of catalysts can also be linked to environmental protection. For example, controlling the speed of reactions with catalysts can play a big role in reducing energy consumption and minimizing carbon dioxide emissions. Therefore, the development of catalyst technology is not just an economic benefit, but also a key technology for sustainable development.
A chemical reaction is basically a process in which the bonds between the atoms of the reactants are broken and new bonds are formed to form products. Therefore, in order for a substance to act as a catalyst, it must have similar bonds to the reactants and similar bonds to the products, rather than being significantly different. For example, if a person named C wants to set up a blind date for his friend A, and he likes A so much that he doesn’t want to pass him on to someone else, B, then A will be more likely to go out with C than B. Conversely, if C doesn’t like A, she wouldn’t set up a blind date in the first place. In chemicals, the platinum group of metals are platinum, palladium, iridium, and osmium. These metals readily form complexes with 16 electrons at the outermost angles of their atoms, but they are quantum mechanically most stable when they have 18 electrons. Therefore, these metals act as a broker of bonds between reactants and products by creating two more bonds to reach the stable 18-electron state, then breaking the bonds again to return to the original 16-electron state.
Because catalysts make it easier and more useful to control chemical reactions, many types of catalysts have been developed for the production of a wide variety of products, not just plastics. However, for many reactions, the exact mechanisms of catalysis are not well understood, so much of the research is still based on simply trying a substance and seeing what happens. In addition, metals such as platinum group metals are too expensive as precious metals to be commercially competitive. In the future, if the mechanism of catalysis is elucidated in detail thanks to the development of various analytical techniques, it will be possible to use various metals other than platinum group metals for chemical reactions. This will allow humans to lead a more materially enriched life by making various objects from materials such as plastics, which can be easily produced at low cost. Furthermore, advances in catalyst technology can play an important role in solving various environmental problems facing humanity, which will give us the opportunity to leave a better planet for future generations.
