@article{DongDuchesneMohanetal.2020, author = {Dong, Yuchan and Duchesne, Paul and Mohan, Abhinav and Ghuman, Kulbir Kaur and Kant, Paul and Hurtado, Lourdes and Ulmer, Ulrich and Loh, Joel Y. Y. and Tountas, Athanasios A. and Wang, Lu and Ali, Feysal M. and Xia, Meikun and Dittmeyer, Roland and Ozin, Geoffrey A.}, title = {Shining light on CO2: from materials discovery to photocatalyst, photoreactor and process engineering}, series = {Chemical Society Reviews}, volume = {49}, journal = {Chemical Society Reviews}, number = {16}, publisher = {Royal Society of Chemistry (RSC)}, issn = {0306-0012}, doi = {10.1039/D0CS00597E}, pages = {5648 -- 5663}, year = {2020}, abstract = {Heterogeneous catalysis, a process in which the reaction of gaseous or liquid chemical reagents is facilitated at the surface of a solid material, is responsible for the majority of industrial-scale chemical and fuel production reactions. The energy required to drive these reactions has historically been derived from the combustion of non-renewable fossil fuels and carries an unavoidably large carbon footprint. More recently, the development of environmentally responsible and sustainable chemical industries is increasingly motivated by greenhouse gas-induced climate change, thus creating demand for eco-friendly heterogeneous catalytic processes. This includes innovative approaches enabled by renewable forms of energy, such as the electrification of chemical and petrochemical processes, utilization of CO2 as a feedstock and the incorporation of light into catalytic reactions. Herein we review the conversion of solar energy to chemical energy using CO2, and describe how the photophysical and photochemical properties of nanostructured metal oxide photocatalysts have been engineered to efficiently incorporate light into heterogeneous gas-solid CO2 hydrogenation reactions. Realizing high photonic and energy efficiencies in these systems has demanded innovation in not only photocatalyst engineering, but also photoreactor and process engineering. Rather than exclusively providing an in-depth discussion of the chemistry and science within each individual study, this Tutorial Review highlights the multidisciplinary character of photocatalysis studies by covering the four essential components of a typical research work in this field (materials engineering, theoretical modelling, reactor engineering and process development) via case studies of the archetypal indium oxide catalyst materials. Through advances in these four components, progress has been made towards the ultimate goal of industrializing the production of CO2-derived chemicals and fuels.}, language = {en} } @article{MohanUlmerHurtadoetal.2020, author = {Mohan, Abhinav and Ulmer, Ulrich and Hurtado, Lourdes and Loh, Joel and Li, Young Feng and Tountas, Athanasios A. and Krevert, Carola and Chan, Chakyu and Liang, Yilei and Brodersen, Peter and Sain, Mohini M. and Ozin, Geoffrey A.}, title = {Hybrid Photo- and Thermal Catalyst System for Continuous CO2 Reduction}, series = {ACS Applied Materials \& Interfaces}, volume = {12}, journal = {ACS Applied Materials \& Interfaces}, number = {30}, publisher = {American Chemical Society (ACS)}, issn = {1944-8244}, doi = {10.1021/acsami.0c06232}, pages = {33613 -- 33620}, year = {2020}, abstract = {Heterogeneous thermal catalytic processes are vital for industrial production of fuels, fertilizers, and other chemicals necessary for sustaining human life. However, these processes are highly energy-intensive, requiring a vast consumption of fossil fuels. An emerging class of heterogeneous catalysts that are thermally driven but also exhibit a photochemically enhanced rate can potentially reduce process energy intensity by partially substituting conventional heat (where fossil fuels are needed) with solar energy. Such catalyst systems have yet to be practically utilized. Here, we demonstrate a compact electrically heated photo- and thermal annular reactor module to reduce CO2 to CO, via the reverse water gas shift reaction. A first-principles-based design approach was taken in developing a SiO2 on an Al photo- and thermal catalyst system for the model photo- and thermal indium oxide hydroxide (In2O3-x(OH)y) catalysts. A 5-fold light enhancement in the CO production rate and over 70 h of stable CO production were achieved. This represents the highest light enhancement effect reported for this model photocatalyst to date. The reactor presented herein allows continuous operation and a significant reduction of 31\% in heater power consumption when provided with an additional 2 suns of irradiation, demonstrating the strong photo- and thermal-harvesting performances of the catalyst system developed in this work.}, language = {en} } @article{HurtadoMohanUlmeretal.2022, author = {Hurtado, Lourdes and Mohan, Abhinav and Ulmer, Ulrich and Natividad, Reyna and Tountas, Athanasios A. and Sun, Wei and Wang, Lu and Kim, Boeun and Sain, Mohini M. and Ozin, Geoffrey A.}, title = {Solar CO2hydrogenation by photocatalytic foams}, series = {Chemical Engineering Journal}, volume = {435}, journal = {Chemical Engineering Journal}, publisher = {Elsevier BV}, issn = {1385-8947}, doi = {10.1016/j.cej.2022.134864}, pages = {11}, year = {2022}, abstract = {Here we report the enhanced light penetration and mass transfer efficiency of photocatalytic foams to convert CO2 to CO. The viability of utilizing a metallic foam as a model photocatalyst support is used to evaluate the photochemical and thermochemical reverse water gas shift reaction catalyzed by photoactive indium oxide hydroxide nanorods uniformly coated on nickel foams. A light-enhanced CO production rate up to 130\% higher than the dark CO production was achieved through enhanced light penetration. A remarkably high thermo- chemical CO production rate of 0.75 mmol gcat 1 h 1 was achieved at 295 ◦C. Whilst several approaches to optimization of photocatalyst morphology at the nanoscale have been successful in extending electron hole-pair lifetime and modifying the site of reactions, these advantages cannot be significantly realized unless microscale to macroscale structuring efforts, that shorten the path length for diffusion of the reactant gas molecule and lengthen photon penetration to these catalytic sites are integrated. The superior catalytic performance of the indium oxide hydroxide nanorods on an optimized coated foam configuration compared to the performance of packed bed and thin film configurations demonstrates the critical importance of using structured supports in scale up of future photocatalytic processes.}, language = {en} }