Where: Saló d'actes, Edifici d'investigació II
Presented by: Prof. Sixto Gimenez
To accelerate the transition to a low-carbon future based on renewable energy sources such as solar and wind, more effort is required to ensure flexible storage and usage options for this intermittent energy. Converting and storing excess renewable electrical energy into chemicals is
essential to this challenge. Hydrogen is a unique chemical and fuel that will play a key role in the transition to low-carbon technologies. With its high energy density and flexibility as a clean energy carrier and chemical feedstock, H 2 and H 2 -based systems can be integrated across a wide energy landscape.
This talk will focus on several electrochemical processes for hydrogen production and utilization. First, we will discuss green hydrogen generation using anion exchange membrane water electrolysis (AEMWE) over NiFe nano-structured catalysts [1]. This technology promises
to use an anion exchange membrane (AEM) to combine the benefits of alkaline and proton exchange membrane (PEM) electrolyzers, producing hydrogen at high current densities and high efficiency using low-cost, non-platinum group catalysts. We will address the technical
challenges related to electrocatalyst materials, membranes, ionomers, and porous transport layers.
Second, we will explore the electro-reforming of glycerol to value-added products with simultaneous hydrogen generation. Glycerol is a main by-product of biodiesel transesterification; for every ton of biodiesel produced, 100 kg of glycerol is generated. The overproduction of crude
glycerol has become a global challenge. Electrochemical oxidation of crude glycerol to value- added products without C–C–C cleavage, along with concurrent cathodic production of H 2 , has been investigated using Ni-based electrocatalysts to tune activity and selectivity [2].
The third topic will cover hydrogen utilization for waste carbon dioxide catalytic transformation into useful chemicals using the electrochemical promotion of the CO 2 hydrogenation reaction.
Heterogeneous catalysis emerges as a promising method for efficiently converting waste CO 2 into valuable chemicals on a large scale. Depending on the reaction conditions, CO 2 hydrogenation can yield a spectrum of products, such as CO, methane, methanol, and higher
hydrocarbons. The key challenge lies in developing cost-effective, active, and stable catalytic systems for this transformation. We will present our strategy to enhance the activity, selectivity, and stability of the catalyst through the electrochemical promotion of catalysis (EPOC)
phenomenon [3]. In EPOC, the catalytic reaction rate and selectivity are altered by applying a current or potential difference across the catalyst deposited on an ionically conductive support.
We will highlight recent examples of EPOC applied to the CO 2 hydrogenation reaction, particularly emphasizing its use with non-noble catalysts, specifically those based on iron (Fe) and copper (Cu), showcasing their relevance and efficacy in driving the methanation and reverse
water gas shift reactions.
1. E. Cossar, A.O. Barnett, F. Seland, R. Safari, G.A. Botton, E.A. Baranova, J. Power Sources. 514 (2021) 230563.
2. M.S.E. Hoauche, K. Hughes, R. Safari, G.A. Botton, E.A. Baranova, ACS Materials and Interfaces, 12, 13 (2020) 15095.
3. P Vernoux, L. Lizzaraga, A. De Lucas-Consuegra, J.-L. Valverde, E.A. Baranova et al. Chem. Reviews. 113, 10 (2013) 8192.
