- Acidic Oxygen Evolution Reaction Activity-Stability Relationships in Ru-Based Pyrochlores ACS CATALYSIS 2020; 10 (20): 12182–96
A non-precious metal hydrogen catalyst in a commercial polymer electrolyte membrane electrolyser.
We demonstrate the translation of a low-cost, non-precious metal cobalt phosphide (CoP) catalyst from 1cm2 lab-scale experiments to a commercial-scale 86cm2 polymer electrolyte membrane (PEM) electrolyser. A two-step bulk synthesis was adopted to produce CoP on a high-surface-area carbon support that was readily integrated into an industrial PEM electrolyser fabrication process. The performance of the CoP was compared head to head with a platinum-based PEM under the same operating conditions (400psi, 50°C). CoP was found to be active and stable, operating at 1.86Acm-2 for>1,700h of continuous hydrogen production while providing substantial material cost savings relative to platinum. This work illustrates a potential pathway for non-precious hydrogen evolution catalysts developed in past decades to translate to commercial applications.
View details for DOI 10.1038/s41565-019-0550-7
View details for PubMedID 31611657
- Robust and biocompatible catalysts for efficient hydrogen-driven microbial electrosynthesis COMMUNICATIONS CHEMISTRY 2019; 2
- Revealing the Synergy between Oxide and Alloy Phases on the Performance of Bimetallic In-Pd Catalysts for CO2 Hydrogenation to Methanol ACS CATALYSIS 2019; 9 (4): 3399–3412
Quantifying the flow efficiency in constant-current capacitive deionization
2018; 129: 327–36
Here we detail a previously unappreciated loss mechanism inherent to capacitive deionization (CDI) cycling operation that has a substantial role determining performance. This mechanism reflects the fact that desalinated water inside a cell is partially lost to re-salination if desorption is carried out immediately after adsorption. We describe such effects by a parameter called the flow efficiency, and show that this efficiency is distinct from and yet multiplicative with other highly-studied adsorption efficiencies. Flow losses can be minimized by flowing more feed solution through the cell during desalination; however, this also results in less effluent concentration reduction. While the rationale outlined here is applicable to all CDI cell architectures that rely on cycling, we validate our model with a flow-through electrode CDI device operated in constant-current mode. We find excellent agreement between flow efficiency model predictions and experimental results, thus giving researchers simple equations by which they can estimate this distinct loss process for their operation.
View details for PubMedID 29161663
Charging and Transport Dynamics of a Flow-Through Electrode Capacitive Deionization System
JOURNAL OF PHYSICAL CHEMISTRY B
2018; 122 (1): 240–49
We present a study of the interplay among electric charging rate, capacitance, salt removal, and mass transport in "flow-through electrode" capacitive deionization (CDI) systems. We develop two models describing coupled transport and electro-adsorption/desorption which capture salt removal dynamics. The first model is a simplified, unsteady zero-dimensional volume-averaged model which identifies dimensionless parameters and figures of merits associated with cell performance. The second model is a higher fidelity area-averaged model which captures both spatial and temporal responses of charging. We further conducted an experimental study of these dynamics and considered two salt transport regimes: (1) advection-limited regime and (2) dispersion-limited regime. We use these data to validate models. The study shows that, in the advection-limited regime, differential charge efficiency determines the salt adsorption at the early stage of the deionization process. Subsequently, charging transitions to a quasi-steady state where salt removal rate is proportional to applied current scaled by the inlet flow rate. In the dispersion-dominated regime, differential charge efficiency, cell volume, and diffusion rates govern adsorption dynamics and flow rate has little effect. In both regimes, the interplay among mass transport rate, differential charge efficiency, cell capacitance, and (electric) charging current governs salt removal in flow-through electrode CDI.
View details for PubMedID 29292999