(36g) Flame Spray Pyrolysis Designed Defective Catalysts for Carbon Dioxide Conversion

Flame
Spray Pyrolysis Designed Defective Catalysts for Carbon Dioxide Conversion

Emma
Lovell*, Rahman Daiyan, Salina
Jantarang, Jonathan Horlyck, Jason Scott and Rose Amal

Particle
and Catalysis Research Group, School of Chemical Engineering, the University of
New South Wales, Sydney, Australia, 2052

*-
e.lovell@unsw.edu.au

Given the current state of
play globally with respect to climate change the mitigation of anthropogenic carbon
dioxide emissions is of key societal importance. The valorization of carbon
dioxide to invaluable industrial chemicals and fuels, such as methane and formate,
has the dual benefit of consuming destructive CO₂ whilst simultaneously
producing valuable products. The catalytic conversion of carbon dioxide can be done
using thermal catalytic and electrocatalytic pathways. In both
of these conversion routes, surface defect sites and oxygen vacancies are
proposed to play a significant role in the activation of CO₂.

Flame spray pyrolysis (FSP) is
a scalable and reproducible method of synthesizing nanomaterials which allows for
control over size, morphology, crystallinity and surface chemistry by simply
tuning the flame input parameters. Given these properties, FSP has vast potential
to produce materials for CO₂ conversion, both thermal and electro-catalytically.

In this work, we utilized FSP
as a powerful tool to tune the surface defects of a range of metal oxides which
were used as catalysts for CO₂ reduction reactions. By varying input
parameters and post-processing methods, we were able to effectively tune the surface
defect sites and oxygen vacancies for a range of materials, including SnO₂
and ZnO, for the electrocatalytic reduction of carbon
dioxide (CO₂RR). By doing so, we were able to control selectivity
and maximise current density. Ultimately this enabled insights into the role of
defect sites in electrocatalytic CO₂ reduction reactions. Further,
we utilised FSP to design CeO₂-based catalyst supports to
systematically control the surface oxygen vacancies of Ni/CeO₂
catalysts for the (photo)thermal conversion of CO₂ to CH₄.
In tuning these, we were able to understand the role of CeO₂ surface
oxygen vacancies in the methanation of carbon dioxide.