New Technology: New Catalyst Can Transform Waste Into Valuable Environmental Protection Products

This new catalyst aims to add functional groups to aliphatic hydrocarbons, which are organic compounds composed of only hydrogen and carbon. These hydrocarbons usually do not mix with water and form independent layers due to lack of functional groups. By adding functional groups to these hydrocarbon chains, the properties of materials can be greatly changed, making them easier to recover.

"Methane in natural gas is the simplest hydrocarbon, with only carbon hydrogen (CH) bond. Oil and polymer have carbon atomic chains connected by carbon carbon (CC) bond," Sadow explained.

Aliphatic hydrocarbons constitute a large number of petroleum and refined petroleum products, such as plastics and engine oils. These materials "have no other functional groups, which means they are not easily biodegradable," Sadow said. "Therefore, for a long time, one of the goals in the field of catalysis is to be able to add these kinds of materials to other atoms, such as oxygen, or to establish new structures from these simple chemicals."

Unfortunately, the traditional method of adding atoms to the hydrocarbon chain requires a large amount of energy input. First, oil is heated and pressurized to "crack" into small building blocks. Next, these components are used to grow the chain. Finally, add the desired atoms to the end of the chain. In this new method, existing aliphatic hydrocarbons can be directly converted at low temperature without cracking.

Sadow's team used a catalyst to break the CC bond in these hydrocarbon chains, while connecting aluminum to the end of the smaller chain. Next, they inserted oxygen or other atoms to introduce functional groups. In order to develop a complementary process, the team found a way to avoid the CC bond breaking step. According to the chain length of the starting material and the ideal characteristics of the product, researchers want to shorten the chain or simply add oxygen functional groups. If CC cracking can be avoided, in principle, the chain can only be transferred from the catalyst to aluminum, and then air can be added to install functional groups.

Sadow explained that the catalyst was synthesized by attaching a commercially available zirconium compound to the commercially available silica alumina. These materials are abundant and cheap on the earth, which is beneficial to potential commercial applications in the future.

In addition, catalysts and reactants also have advantages in sustainability and cost. Aluminum is the most abundant metal on the earth, and the synthesis of aluminum reactants used will not produce waste by-products. Zirconia based catalyst precursors are stable in air, easily available, and activated in the reactor. Therefore, unlike many early organometallic chemistry, which is extremely sensitive to air, this catalyst precursor is easy to handle.

This chemical reaction is a step towards influencing the physical properties of various plastics, such as making them stronger and easier to color

Sadow attributed the success of this project to the cooperative nature of iCOUP. The Pellas group of Ames National Laboratory used nuclear magnetic resonance (NMR) spectroscopy to study the structure of the catalyst. Coates, LaPointe and Delferro teams from Cornell University and Argonne National Laboratory studied the structure and physical properties of polymers. The Peters group at the University of Illinois has statistically modeled polymer functionalization.