The_Catalyst_Review_October_2023 - 6

Process News
New Catalyst Could Improve Conversion of Waste CO2
Hydrogenation of CO2
to Useful Formate
economic route for the utilization of this greenhouse gas. Non-precious metal-based catalysts for the CO2
to formate, an important chemical widely used in leather, textile, mining industry, etc., is an attractive atomhydrogenation
to formate
suffered from either low activity or low stability. It's still a challenge to develop low-cost and high-performance catalysts for CO2
hydrogenation to formate. Recently, a research group led by Prof. Deng Dehui from the Dalian Institute of Chemical Physics (DICP)
of the Chinese Academy of Sciences (CAS) developed an edge-rich molybdenum disulfide (ER-MoS2
to formate with superior activity and high stability. In this study, the ER-MoS2
) catalyst for CO2
was enabled via a new water-mediated hydrogenation mechanism, in which surface OH* and H* species from H2
the edge-sulfur vacancies served as moderate hydrogenating agents with residual O* reduced by H2
9/18/2023.
TMD Catalyst Improves Electrochemical
Water Splitting
A research team led by the City University of Hong Kong
has constructed a highly efficient electrocatalyst that
can significantly boost hydrogen production through
electrochemical water splitting. The electrocatalyst employs
transition-metal dichalcogenide (TMD) nanosheets with
unusual crystal phases as supports. The team created an
electrocatalyst employing transition-metal dichalcogenide
(TMD) nanosheets with unusual crystal phases as supports.
In the electrocatalytic hydrogen evolution process in acidic
conditions, the electrocatalyst showed high activity and
good stability. TMD nanosheets have piqued the curiosity of
researchers as an emerging two-dimensional (2D) material due
to their unusual physical and chemical features. It has been
discovered that phase is a crucial component in determining
the characteristics and functionalities of TMD nanosheets.
Molybdenum disulfide (MoS2
for example, has a semiconductor property, but MoS2
) with the standard 2H phase,
with
the atypical 1T or 1T' phase has a metallic or semi-metallic
property, and so has strong conductivity. The research group
has successfully generated a variety of high-phase-purity
and high-quality TMD crystal materials with unconventional
1T′ phase using novel techniques such as solid-gas reactions
and salt-assisted synthesis. These nanomaterials have a high
potential for use in optoelectronic devices, catalysis, energy
storage, and superconductivity due to their unique semimetallic
characteristics. Source: Azonano, 9/14/2023.
Gold Nanocluster-rich Titanium Dioxide
Photocatalyst Enables the Oxidative
Coupling of Methane
Researchers at University College London, University of
Liverpool have recently developed a new photocatalyst
that could advance the oxidative coupling of methane. This
photocatalyst is based on titanium dioxide (TiO2
, producing their promising new photocatalyst.
In initial tests, an optimized sample of their photocatalyst
appeared to perform remarkably well, converting methane
into C2
reaction conditions. The researchers reported a methane
conversion rate of 1.1 mmol h−1
, C2
apparent quantum efficiency of 10.3 ± 0.6%. The high C2
C2+
/
yield rate was likened to benchmark thermal catalysts in
oxidative coupling of methane (OCM) processes operated
at high temperature (>680 °C). Au nanoparticles were shown
to prolong TiO2
O2
photoelectron lifetimes by a factor of 66 for
reduction, together with Au acting as a hole acceptor
and catalytic center to promote methane adsorption, C-H
activation and C-C coupling. The proposed photocatalyst,
Au60s/TiO2
, was found to outperform many previously
reported catalysts that can trigger this reaction, in terms of
stability, methane conversion rate and yield of C2
. Notably,
the team's photocatalyst is also easy to fabricate, which could
facilitate its large-scale production and deployment. Source:
Phys.org, 9/13/2023.
H2U Completes Performance and Durability Tests for Non-iridium Catalysts
H2
edges were the active sites and the selective production of formate
O dissociation on
hydrogenation
with abundant edges delivered a high TOF of 780.7 h-1
with formate selectivity of over 99% at 200 °C, and exhibited a good stability. Multiple experimental characterizations combined with
theoretical calculations revealed that sulfur vacancies at MoS2
. Source: Technology Networks,
) loaded with
gold (Au) nanoclusters. Using a rapid sputtering method, the
researchers were able to homogenously load Au nanoclusters
onto TiO2
at a high rate and without requiring particularly harsh
selectivity of ~90% and
U Technologies has performed durability tests on new, lower-cost, iridium-free catalyst materials that demonstrate a projected
lifetime of 25,000 hr. This durability milestone promises to address supply chain bottlenecks for sustainable H2
production with proton
exchange membrane (PEM) electrolyzers. Discovering non-iridium catalysts for commercial applications has been challenging, as novel
materials often degrade rapidly under the harsh acidic conditions of the oxygen evolution reaction (OER). With a baseline of over
4,000 hr of continuous operation thus far, H2
lifetimes of more than 25,000 hr. H2
paired with curtailed renewables. Source: H2
Tech, 9/19/2023.
U's iridium-free catalysts, tested at 10x higher current density, are demonstrating projected
U catalysts are projected to last at least 6 yr for targeted applications, such as in PEM electrolyzers
6
The Catalyst Review
October 2023

http://www.Phys.org

The_Catalyst_Review_October_2023

Table of Contents for the Digital Edition of The_Catalyst_Review_October_2023