Page 170 - CW E-Magazine (28-1-2025)

Special Report

tionally polyethylene-1,4-cyclohexane
dicarboxylate, with lower molecular
weight. The partially hydrogenated
product has thermal stability and mecha-
nical strength comparable to PET,
along with superior extensibility, bar-
rier properties, and (bio) degradability
precursor under the NH decomposi- cluster size. (ACS Sustainable Chem. in acidic, alkaline solutions. (Angew.
3
tion reaction condition. This non-noble Eng., 2024; DOI: 10.1021/acssusche- Chem. Intl. Ed., 2024; DOI: 10.1002/
catalyst has higher activity among such meng.4c03964). anie.202418157).
catalysts. This is a remarkable develop-
ment. (Angew. Chem. Intl. Ed., 2024; Catalytic activity and stability Production of branched
DOI: 10.1002/anie.20241695). of NiPt/C catalysts for the alkanes by upcycling of waste
Supported Pt metal clusters synthesis of isobutanol (IB) polyethylene over controlled
with different sizes on from methanol (M)/ethanol acid sites of SO /ZrO /Al O 3
2
4
2
TiO nanosheets: Efficient (E) [This column has covered many papers
2
catalytic dehydrogenation of J. Pasel et al have reported the use of on valorising waste polyethylene and
dodecahydro-N-ethylcarbazole bi-metallic NiPt catalysts supported on this subject continues to attract atten-
(DDHEC) activated carbon for the title synthesis, tion.]
[This column has covered some papers which is interesting and potentially use- W. Han et al have worked on getting
on H carriers like dibenzyl toluene, ful. Kinetic parameters were determined. branched alkanes which have higher
2
carbazole, etc and a key factor is the Temperature of 165°C was suitable and octane number compared to linear for
ease with which dehydrogenation can there was no ageing of the catalytic blending with petrol. A one-pot process
be done efficiently and cheaply under active species. (Catalysis Sci. Technol., is reported to convert to convert poly-
relatively mild conditions.] 2024; DOI: 10.1039/D4CY01061B). ethylene into gasoline-range hydrocar-

Z. Yang et al have emphasised the Hydrogenating PET into
importance of supported metal clusters degradable polyesters
(SMCs), which possess unique elec-
tronic and geometric features that give Z. Guo et al have come out with a diffe-
improved catalysis. Pt loading was at rent strategy of dealing with PET waste.
2.5 wt% and Pt/TiO catalysts contain- Transforming end-of-life PET into
2
ing Pt clusters with sizes ranging from (bio) degradable polyester offers a novel
1 to 4 nm were obtained. Pt cluster size approach. These authors have carried
of 1.72 ± 0.20 nm was found to be good out part hydrogenation of the aromatic
and there were no byproducts. The rings without depolymerisation. With
size of Pt clusters is important. DFT deeper hydrogenation, pronounced bons (C -C ) with yield of 73.3% over
4
13
calculation confirmed the suitable Pt depolymerisation occurs giving addi- the title catalyst, at 280°C. Further,
DFT calculation were done. (Angew.
Chem. Intl. Ed., 2024; DOI: 10.1002/
anie.202417923).
Recycling polyethylene
to high-purity H under
2
ambient conditions via
mechanocatalysis

G-F. Han et al have worked on the title
process using manganese as catalyst
at as low a temperature as 45°C and
is far superior to doing only thermo-

170 Chemical Weekly January 28, 2025

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