Scientists break down plastic using a simple, inexpensive catalyst and air

Technical process and capabilities

• Catalyst is activated carbon/molybdenum dioxide operating around 265 °C in air with ambient moisture, converting PET to terephthalic acid (TPA) and acetaldehyde.
• Paper reports ~94% of possible TPA recovered in 4 hours at 1 atm, including from “real-world” inputs like bottles, textiles, colored and mixed plastics.
• Several commenters note these temperatures are comparable to PET melting and existing recycling/molding processes, so not extreme by industrial standards.
• Compared with pyrolysis that yields mixed petrochemicals, this gives relatively pure monomers that can be re‑polymerized into PET.

Economics, energy, and scalability

• Article headlines “simple, inexpensive catalyst,” but gives no explicit process cost; commenters criticize this and note that cheap virgin feedstocks (~$0.50/lb for BTX-type chemicals) are the real benchmark.
• Energy input for heating and the 4‑hour residence time raise questions about throughput and capital cost; continuous processes can help but Little’s Law still applies.
• Upstream logistics (collection, sorting, cleaning) are seen as the dominant cost for any PET recycling, often outweighing reaction/separation costs.
• Mechanical PET recycling remains cheaper when possible because it avoids depolymerization and re‑polymerization steps.
• Heat recovery and general energy integration are assumed standard in industrial practice, so not a unique advantage here.

Mixed plastics, sorting, and other polymers

• A key appeal is extracting PET from mixed streams without perfect sorting; paper explicitly discusses this use case.
• Commenters stress that “plastic” is many materials with different properties; PET (#1) and HDPE (#2) are relatively easy, but most others are not, and sorting remains a major hurdle.
• There is discussion of mechanical closed‑loop PET bottle recycling, including existing 100% recycled bottles and textile fibers, but also concern that fabrics are major microplastic sources.

Microplastics and health concerns

• Multiple comments focus on microplastics from clothing, tires and bottles, and on emerging evidence of plastics in human organs and infants.
• Some argue landfilled “mountains” of plastic are less problematic than diffuse microplastic pollution; others see plastic pollution overall as an environmental catastrophe.

Policy, externalities, and alternatives

• Strong thread on pricing externalities: proposals for lifecycle plastics taxes, tariffs on virgin plastic, and extended producer responsibility.
• Counter‑arguments emphasize the difficulty and bureaucracy of fully internalizing cleanup costs in practice.
• Debate over bans vs price signals: targeted phase‑outs of easily replaceable items (e.g., confetti, straws) vs blanket rules that would make essentials unaffordable.
• Biodegradable/“eco” plastics are criticized as often underperforming, requiring industrial composting, and contaminating recycling streams; some see them as greenwashing.

Overall sentiment

• Many are cautiously impressed by the chemistry and especially the ability to recover monomers from mixed PET streams.
• At the same time, there is fatigue with recurring “breakthrough” stories that omit timelines, costs, and realistic paths to large‑scale impact amid ever‑growing plastic production.