Page 182 - CW E-Magazine (28-11-2023)

Special Report

and there is a crucial need for a better
understanding to design catalysts tailored
to the plasma environment and design
plasma reactors with optimal transport
of plasma species to the catalyst surface
and tune the plasma conditions so they
work in optimal synergy with the cata-
lyst. Other areas are: continuous-fl ow
photocatalysis; electrochemical fl ow
catalysis; microwave fl ow catalysis;
and ultrasound fl ow activation. A series
of examples are discussed with the aim
of industrialisation. (Catalysis Today, Highly effi cient synthesis of Highly selective catalytic
2023, 420, 1 August, 114180). high-value olefi ns from syngas oxi-upcycling of polyethylene
st
Non-enzymatic catalytic derace- over layered Fe-Mn/Magadiite to aliphatic dicarboxylic acid
misation (MAG) catalyst under a mild H2-free process

FDA insists on the use of the desired S. Xue et al have reported high olefi n/ K. Wang et al have come out with an
optically active API, instead of the racemic paraffi n (O/P) ratio in the conversion of interesting and potentially exploitable
mixture. K-K. Qiao et al have discussed syngas to high-value olefi ns (HVOs). strategy where Ru/TiO catalyst (hetero-
2
the conversion of a racemic mixture into MAG is a layered silicate material with geneous) is used for LDPE. It is
a single enantiomer of the same com- active SiOH, which increases the inter- interesting that conversion can reach
pound in theoretically 100% yield by layer charge density and ion-exchange 95% in 24 hours under a pressure of 1.5
increasing the quantity of one enantiomer ability. MGA-supported Mn-modifi ed MPa air at 160 C with 85% of the liquid
o
at the expense of the other. This paper Fe O microsphere catalyst gives an product yield, which is mainly low mole-
3
4
discusses pure chemical reaction condi- excellent conversion of CO at 76.5% cular weight aliphatic dicarboxylic acid.
tions avoiding biocatalysed deracemisa- and HVO selectivity, with a high O/P This is a novel way of upcycling LDPE.
tion and spontaneous deracemisation by ratio of 5.02 and low CH selectivity of (Angew. Chem. Intl. Ed.; DOI: 10.1002/
4
crystallisation. Thus, redox-driven dera- 16.1%. The mechanism is explained. anie.202301340).
cemisation enabled by sequential oxida- (Chem. Eng. Technol., 2023; DOI:
tion/reduction operation or a compatible 10.1002/ceat.202200533). Suitable commercial catalysts
redox system and photochemical dera- for the synthesis of oxymethy-
cemisation via selective energy transfer, Identifying the performance lene dimethyl ethers (OMDEs)
hydrogen-atom and proton transfer are descriptor in direct syngas
discussed. The latter has gained a big conversion to long-chain α-ole- F. Mantei et al have referred to OMDEs
breakthrough and open up this strategy. fi ns (AOs) over Ru-based that have diesel fuel like properties with
(J. Catalysis, 2023, 422, June, 99-116).
catalysts promoted by alkali almost soot-free combustion, which
Iron-catalysed intramolecular metals can also enable a reduction of nitrogen
C-H amination for the syn- oxides. They are also good solvents
thesis of N-H carbazoles and H. Yu et al have worked on the title (even for fuel cells). These products ca
indoles subject in view of making AO’s with- be made from methanol. Various ion
out ethylene oligomerisation. The title exchange resins, zeolites and Nafi on
Z-L. Wang et al have reported an aero- catalysts were properly characterised catalysts were studied at 60 C for the
o
bic oxidation for the title reactions. by XRA and PES, and CO diffuse aqueous reaction systems; methanol/
There is compatibility with functional refl ectance IR FT. Adjustments could paraformaldehyde and the anhydrous
groups. A wide range of carbazoles and be made to give lower olefi ns at 50% reaction system of OMDME/trioxane.
indoles in good yields are reported. to long-chain AO at 85.8% by manip- It seems ion exchange resins are the
All carbazoles are made from 2-cyclo- ulating alkali metal promoters. (ACS most suitable for the above reaction.
hexenyl aminoarenes. (Green Chem., Catalysis, 2023, 13 No.6, 3949-3959; (Reaction Chem. Eng., 2023/re/
2023; DOI: 10.1039/D3GC00518F). DOI:10.1021/acscatal.2c06158). D2RE00508e).

182 Chemical Weekly November 28, 2023

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