Page 169 - CW E-Magazine (27-2-2024)

Special Report

Toluene alkylation with The management of by-products is
CH OH to give p-xylene (PX) important and conversion to useful pro-
3 ducts needs to be studied. The reduction
This process has become commercial in CO production has got centre-stage.
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and D. Parmar et al have studied the The steam reforming process may be
impact of medium-pore zeolite topology coupled to high temperature solar energy
on this conversion. Seven different zeo- or electrical heating (renewable electri-
lites were made: 1-dimensional zeolite city).
ZSM-23; 2-dimensional zeolites TNU-
10 and MCM-22; and 3-dimensional It has become more difficult to intro-
zeolites ZSM-11, ZSM-5, TNU-9 and duce new technology to the process
industry. The catalyst performance may tion energy and a low NH hydrogena-
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also be affected by a complex interac- tion barrier. (Cat. Sci. Technol., 2023;
tion with mass and heat transfer in the DOI: 10.1039/D3CY00462G).
reactor arrangement.
Graphdiyne (G)-based multi-
There is new “society pull;” e.g., clean-
a: Structure of the periodic 96 T HZSM-5 model; scale catalysts for NH synthe-
b: illustration of the toluene direct methylation ing of exhaust gas. There is also “reg- sis 3
reaction at the Brønsted acid site ulatory push”. Curiosity driven funda-
IM-5. MCM-22 proved to give highest mental research is very important. S. Zhao et al have referred to G, a sp/
selectivity of 60% PX and exceptio- (Catalysis Today, 2023, 423, 113878; sp -cohybridised two-dimensional
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nally long lifetime; it has the total turn- DOI: 10.1016/j.cattod.202208020). all-carbon material having many unique
over four times that of the second-best and fascinating properties of alkyne-
catalyst, zeolite IM-5. It is interesting Ammonia (NH ) rich structures, large π-conjugated
3
to note that high pressure is beneficial [This column has covered a significant system, uniform pores, specific un-
for its performance due to the nature number of papers in recent years on evenly-distributed surface charge, and
of coke formation. (Cat. Sci. Technol., new developments in this more than a incomplete charge transfer properties
2023; DOI: 10.1016/D3CY00557G). century old epoch making process. The provide potential in practical applica-
add-on Ru-based catalyst is covered. tions, e.g., catalysis. This has been con-
Challenges to industrial cata- Haber got Nobel Prize and Ertl also got sidered for N -fixation and NH synthe-
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lysis Nobel Prize for explaining functioning sis at room temperatures and ambient
3
of iron-based catalyst of the original pressures. This review gives an update
J.R. Rustrup-Nielson has given a suc- recipe of Haber.]
cinct account of this exceedingly for multi-scale catalysts and its use in
important subject for practically all Correlation between the struc- NH synthesis. Future perspectives are
3
industrially practiced processes. Even tural features and intrinsic given. (ChemSusChem; DOI: 10.1002/
many environmental problems have cssc.202300861).
been tackled through catalysis. This activity trend of Fe surfaces
area is multi-disciplinary involving re- for NH synthesis Catalysts informatics: paradigm
3
action kinetics, surface science, reactor shift towards data-driven cata-
modelling and the technologies for the J. Chen et al have used DFT to cal- lyst design
manufacture of catalysts. Spectroscopic culate the reaction energetics on
methods are crucial for characterising various Fe surfaces in conjunction with K. Takahashi et al have referred to de-
catalysts. There is a need for better microkinetic analyses to examine the signing catalysts as a challenging task.
links between academia and industry. activity of the Fe surfaces. The order To overcome these difficulties, cata-
of activity is Fe (111) > Fe (211) > Fe lysts informatics has been proposed as
There are a number of “dream” processes (210) > Fe (100) > Fe (110). It seems an alternative to design and understand
looking for breakthrough in catalysis; that the activity trend is correlated to catalysts and this leads to designs from
e.g., direct conversion of CH to CH OH. the barrier of the rate determining step, trends and patterns found in catalysts
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3
This area has entered new fields like N dissociative adsorption barrier, etc. data. Three concepts are introduced:
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electrochemical catalysis in fuel cells An ideal catalyst for NH synthesis experimental catalysts database; know-
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and for electrolysis of water and CO . should possess both a low N activa- ledge extraction from catalyst data via
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Chemical Weekly February 27, 2024 169

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