A first-of-its-kind catalyst mimics natural processes to break down plastics

October 19, 2020

While plastics recycling is not new science, current processes don't make it economically worthwhile-- waste plastics get "down-cycled" into lower grade, less useful material. It's a challenge that continues to be an obstacle in tackling a growing global pollution crisis in single use plastics.

A multi-institutional team of scientists led by the U.S. Department of Energy's Ames Laboratory has developed a first-of-its-kind catalyst that is able to process polyolefin plastics such as polyethylene and polypropylene, types of polymers widely used in things like plastic grocery bags, milk jugs, shampoo bottles, toys, and food containers. The process results in uniform, high-quality components that can be used to produce fuels, solvents, and lubricating oils, products that have high value and could potentially turn these and other used plastics into an untapped resource.

"We've made a big step forward with this work," said Aaron Sadow, a scientist at Ames Laboratory and the Director of the Institute for Cooperative Upcycling of Plastics (iCOUP). "We hypothesized that we could borrow from nature, and mimic the processes by which enzymes precisely break apart macromolecules like proteins and cellulose. We succeeded in doing that, and we're excited to pursue optimizing and developing this process further."

The unique process relies on nanoparticle technology. Ames Lab scientist Wenyu Huang designed a mesoporous silica nanoparticle consisting of a core of platinum with catalytic active sites, surrounded by long silica pores, or channels, through which the long polymer chains thread through to the catalyst. With this design, the catalyst is able to hold on to and cleave the longer polymer chains into consistent, uniform shorter pieces that have the most potential to be upcycled into new, more useful end products.

"This type of controlled catalysis process has never before been designed based on inorganic materials," Huang, who specializes in the design of structurally well-defined nano-catalysts. "We were able to show that the catalytic process is capable of performing multiple identical deconstruction steps on the same molecule before releasing it."

Ames Laboratory's solid state NMR expert Fred Perras' measurements allowed the team to scrutinize the catalyst's activity at the atomic scale, and confirmed that the long polymer chains moved readily through the catalyst pores in the manner resembling the enzymatic processes that the scientists were aiming to emulate.

This research will be expanded and continued under direction of the Institute for Cooperative Upcycling of Plastics (iCOUP), led by Ames Laboratory. iCOUP is an Energy Frontier Research Center consisting of scientists from Ames Laboratory, Argonne National Laboratory, UC Santa Barbara, University of South Carolina, Cornell University, Northwestern University, and the University of Illinois Urbana-Champaign.
-end-
The research is further discussed in the paper, "Catalytic upcycling of high-density polyethylene via a processive mechanism," authored by Akalanka Tennakoon, Xun Wu, Alexander L. Paterson, Smita Patnaik, Yuchen Pei, Anne M. LaPointe, Salai C. Ammal, Ryan A. Hackler, Andreas Heyden, Igor I. Slowing, Geoffrey W. Coates, Massimiliano Delferro, Baron Peters, Wenyu Huang, Aaron D. Sadow, and Frédéric A. Perras; and published in Nature Catalysis.

Ames Laboratory is a U.S. Department of Energy Office of Science national laboratory operated by Iowa State University. Ames Laboratory creates innovative materials, technologies and energy solutions. We use our expertise, unique capabilities and interdisciplinary collaborations to solve global problems. DOE's Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

DOE/Ames Laboratory

Related Plastics Articles from Brightsurf:

Bioplastics no safer than other plastics
Bioplastics contain substances that are as toxic as those in ordinary plastics.

A first-of-its-kind catalyst mimics natural processes to break down plastics
A team of scientists led by the U.S. Department of Energy's Ames Laboratory has developed a first-of-its-kind catalyst that is able to process polyolefin plastics, types of polymers widely used in things like plastic grocery bags, milk jugs, shampoo bottles, toys, and food containers.

Plastics, waste and recycling: It's not just a packaging problem
Discussions of the growing plastic waste problem often focus on reducing the volume of single-use plastic packaging items such as bags, bottles, tubs and films.

'Critical' questions over disease risks from ocean plastics
Key knowledge gaps exist in our understanding of how ocean microplastics transport bacteria and viruses -- and whether this affects the health of humans and animals, researchers say.

Plastics, pathogens and baby formula: What's in your shellfish?
The first landmark study using next-generation technology to comprehensively examine contaminants in oysters in Myanmar reveals alarming findings: the widespread presence of human bacterial pathogens and human-derived microdebris materials, including plastics, kerosene, paint, talc and milk supplement powders.

Chemists make tough plastics recyclable
MIT chemists have developed a way to modify thermoset plastics with a chemical linker that makes it much easier to recycle them, but still allows them to retain their mechanical strength.

The many lifetimes of plastics
Many of us have seen informational posters at parks or aquariums specifying how long plastics bags, bottles, and other products last in the environment.

Recycling plastics together, simple and fast
Scientists successfully blended different types of plastics to be recycled together, providing a solution to the environmental problem of plastic waste and adding economic value to plastic materials.

Water replaces toxins: Green production of plastics
A new way to synthesize polymers, called hydrothermal synthesis, can be used to produce important high-performance materials in a way which is much better for the environment.

Untwisting plastics for charging internet-of-things devices
Scientists are unraveling the properties of electricity-conducting plastics so they can be used in future energy-harvesting devices.

Read More: Plastics News and Plastics Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.