A simpler path to a catalyst

Researchers at ETH Zurich developed a new synthesis procedure for a catalyst. This procedure may be used for the large-scale production of, for instance, plastics from renewable resources in an environmentally friendly and efficient manner.

It started with an idea of Ive Hermans, Assistant Professor at the Institute of Chemical and Bioengineering: The chemist and his co-workers were looking for a new synthesis procedure for an important catalyst for the chemical industry. To date, the synthesis of the catalyst occurs in a very complex and error-prone procedure. The ETH researchers discovered a far more convenient two-step procedure, which is more suitable for large-scale production.

The catalyst in question is a zeolite, a powdery, porous, particulate material. Like all catalysts also this substance can accelerate a certain reaction and/or steer it towards a desired product. Hermans and his co-workers wanted to develop a catalyst that facilitates oxidation reactions and can thus be used for the preparation of so-called lactones from ketones.

The use of a catalyst for such reactions has many advantages. “The preparation of lactones, for instance, is time-intensive and expensive, as acids are formed as side-products”, says Hermans. By using a tin containing zeolite as a catalyst instead, it becomes possible to use hydrogen peroxide as an oxidation reagent so that water is the only side-product. This method has not been implemented industrially so far, due to the time-consuming synthesis procedure of the special zeolites: the process requires 40 days. In addition, the procedure is difficult to control and can easily fail. Experiments have shown that the newly prepared zeolite contains more tin than conventionally prepared catalysts. Due to that, the catalyst is significantly more efficient.

In cooperation with an industrial partner, the ETH researchers want to optimize the preparation procedure for large-scale applications. In the future, the catalyst could be used for the industrial synthesis of starting materials required for important plastics. One example would be the preparation of polylactic acid from renewable resources. Polylactic acid is being used in plastic packing materials or foil. “The demand for plastics made from renewable resources will strongly increase as soon as crude oil – the basis of many plastics – will become more rare and expensive”, explains Hermans. “With our catalyst, it is possible to produce such products on a large scale in a much more environmentally friendly way. “

What Are the Facts of Zeolite?

Minerals can combine and show up in nature in a number of different forms. They can bind together to create unique compounds or be found in their pure form in different geographical or environmental locations. Zeolite is a product that contains a clinoptilolite zeolite molecule that is shaped in the form of a honeycomb and has a naturally negative charge that is used to remove metal toxins from the body.

Zeolites are not so easy to immediately identify because of the fact that they resemble simple rocks and crystals. It is a category of mineral which carries a specific set of characteristics. These minerals are porous and have the capability to absorb, be used as molecular sieves, and have catalytic and ion-exchange properties. When you look at a zeolite up close using a microscope you will notice that whatever it looks like, its surface will be covered in tiny holes or pores.

Natural zeolites can be found in one of two different places. The first is where volcanic rock and ash have mixed together. When this mixture interacts with water that has a high pH level, making it alkaline water, zeolites are formed in rock-like formations. In shallow marine basins, zeolites can also crystallize, though this process takes thousands of years. The water is full of minerals that will alkalize over time and eventually form the microporous zeolite framework.

Since zeolite structures can be designed to filter a particular sized substance, zeolite is used as a sieve or filter to purify or trap impurities. Zeolites are found in machines that make medical-grade oxygen and purify water. In the petrochemical industry they are altered through ion-exchange and become a hydrogen form of zeolite that are powerful acids and can cause acid-catalyzed reactions used in the separation of crude oil.

Zeolite (CAS No. 1327-44-2) has found use in a number of different fields and applied in various situations in them. Because of the tiny pores that they are made up of, they are perfect for trapping or filtering various elements and ions. In the home, they are commonly found as part of water filters. Chemsist also use zeolites to trap or filter certain molecules, since only very small ones can pass through a zeolite’s pores. They are also used in soil purification and to trap solar rays in order to collect heat.

Zeolite molecules are formed from hardened lava that reacts with salt over thousands of years and is completely safe to use. Zeolite is not approved by the Federal Drug Administration (FDA) to treat cancer or any other serious medical condition. However, the FDA has placed Zeolite on the list of generally recognized safe products.Zeolite should be used at your own risk.