The Catalyst Review June 2020 - 18


Ishant Khurana, PhD

Research Scientist Specialist, Catalysis Department, Braskem America, Inc.
Ishant Khurana graduated with a bachelor's degree in chemical engineering from the Institute of Chemical
Technology (Mumbai, India) in 2014 and received his PhD in chemical engineering from Purdue University in
2019 under the supervision of Prof. Fabio H. Ribeiro. His research focused on experimental catalysis research
using an integrated approach involving material synthesis, active site characterization, and catalytic evaluation/
reaction kinetics which involved close collaboration with Cummins Inc. and a modeling group at the University of
Notre Dame. His thesis titled, "Catalytic Consequences of Active Site Speciation, Density, Mobility, and Stability
on Selective Catalytic Reduction of NOx with Ammonia over Cu-Exchanged Zeolites," involved a fundamental
investigation of nature of catalytic active sites and reaction mechanism. In order to continue applying and building
his catalysis expertise in a collaborative R&D environment, Ishant joined Braskem, where he is currently developing more active,
selective, and stable catalysts to intensify basic chemical upgrading reaction(s). He can be reached at

The Catalyst Review asked Dr. Khurana to provide his perspective on what he believes to be the
greatest challenges that industry faces regarding the use of current catalyst technology.
Catalyst technology is prevalent in a vast majority of industrial applications ranging from petroleum refining, chemical, and
polymer production (energy, materials, food, and medical industries), environmental emission abatement, and more recently
in the transition to and development of cleaner, renewable and sustainable energy sources. Even though catalyst technology
is indispensable due to such widespread extensive application, catalysis science technology is complex owing to its multidisciplinary nature (chemistry, material science, and biotechnology) and the need to manipulate the nature of catalyst at
the atomic level. While homogeneous catalysis encounters challenges with catalyst recovery/recycling and catalyst thermal
stability, heterogenous catalysis faces challenges with not so well-defined active sites and catalyst diffusivity. In addition, there
are some major challenges shared by homogeneous as well as heterogeneous catalysts, which include catalyst deactivation
(particularly in heterogeneous catalysis), selectivity-conversion limit/trade-off, and scarcity of intrinsic (scale-independent)
reaction kinetics required for the scale-up of catalyst technology.
Catalyst deactivation is the partial/complete loss of activity and/or selectivity as a function of reaction time. It can be classified
into four types: sintering, poisoning, coking/fouling, and mechanical straining. It poses a significant challenge in many
industrial catalytic processes, as it necessitates the addition of a catalyst regeneration unit/cycle and/or periodic replacement
of costly/precious catalyst. A better understanding of the mechanism of deactivation at the atomic level during working
reaction conditions (in-situ and in operando) would aid in the rational design of a more stable and robust catalyst.
The selectivity-conversion limit or trade-off is another challenge encountered in cases where the reaction product is more
reactive than the reactant on the catalyst, subjecting the given catalytic reaction to an upper limit on the yield of the desired
product. One such example is the direct and selective/partial oxidation of methane to methanol, wherein C-H bond in
methanol has higher activity than in methane. Recent work investigating so-called "dynamic" catalysts based on catalytic
resonance theory (as opposed to conventional catalysts), is striving to break the industrial selectivity limits, and thus,
increasing the catalyst performance and cost-efficiency.
Lastly, the scarcity of intrinsic reaction kinetics required for scaling up a catalyst technology is another challenge. Fundamental
investigation of reaction mechanisms and kinetics using laboratory-scale reactors can be time-consuming but is necessary to
measure the intrinsic/actual reaction kinetics carefully. The true reaction kinetics includes reaction turnover rate (normalized
with the correct number of active sites and free of heat/mass transfer effects, particularly in heterogeneous catalysis), reaction
orders concerning reactants/products, activation energy, and pre-exponential factor. It is essential to obtain the structurefunction relationship better, fairly compare the performance of different catalysts as well as to get the predictive kinetic/
micro-kinetic model (valid over a wide range of conversion), which can be further utilized for the scale-up of a given catalytic

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The Catalyst Review											

June 2020

The Catalyst Review June 2020

Table of Contents for the Digital Edition of The Catalyst Review June 2020

The Catalyst Review June 2020 - cover
The Catalyst Review June 2020 - contents
The Catalyst Review June 2020 - 1
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