Search for: All records

Carbon reactive capture and conversion offers a sustainable route to valuable chemicals and fuels while aiding GHG reduction. Direct electrochemical conversion of capture solutions like bicarbonate avoids the energy demands... 

A MOF-derived CoS_xcatalyst enables efficient sulfide oxidation and nitrate reduction, offering an energy-saving strategy for ammonia synthesis and pollutant remediationviabifunctional electrolysis. 

Greenhouse gas emissions present a significant challenge to humanity, and utilizing renewable electricity to convert emitted CO2 into value-added products offers a promising solution; however, traditional CO2 capture and regeneration processes remain energy-intensive, restricting the overall system efficiency and decarbonization efficacy. In this study, an advanced direct reduction of captured CO2 with large current densities for formate electrosynthesis was demonstrated without the need for CO2 regeneration or compression. The bismuth nanosheet (DRM-BiNS) was synthesized by direct reduction of a Bi-based MOF, representing a new class of catalytic materials with a large surface area and interconnected pores, suitable for the direct reduction of captured CO₂. By seamlessly combining experimentation and simulation, insights into the structure-parameter-performance relation were acquired in a flow cell setting, including critical membrane-electrode distance, cell orientation, and pumping flow rate. Important flow-cell components, such as catholyte volume, electrode substrate, membrane choice, and ionomer type, were also carefully examined to enhance the cell performance. In sharp contrast to prior studies limited to current densities below 20 mA/cm² in bicarbonate-based captured CO2 solutions, this work demonstrates a remarkable current density of 300 mA/cm² with an FE to formate comparable to the case with gas-fed CO2 reduction. Moreover, the process sustained an FE above 50% at a high current density of 500 mA/cm². The DRM-BiNS catalyst exhibited outstanding selectivity, activity, and stability, significantly outperforming oxide-derived bismuth nanosheets (OD-BiNS) in captured CO2 reduction. These findings offer critical insights into the development of sustainable and scalable CO2 utilization technologies. 

Greenhouse gas emissions present a significant challenge to humanity, and utilizing renewable electricity to convert emitted CO2 into value-added products offers a promising solution; however, traditional CO2 capture and regeneration processes remain energy-intensive, restricting the overall system efficiency and decarbonization efficacy. In this study, an advanced direct reduction of captured CO2 with large current densities for formate electrosynthesis was demonstrated without the need for CO2 regeneration or compression. The bismuth nanosheet (DRM-BiNS) was synthesized by direct reduction of a Bi-based MOF, representing a new class of catalytic materials with a large surface area and interconnected pores, suitable for the direct reduction of captured CO₂. By seamlessly combining experimentation and simulation, insights into the structure-parameter-performance relation were acquired in a flow cell setting, including critical membrane-electrode distance, cell orientation, and pumping flow rate. Important flow-cell components, such as catholyte volume, electrode substrate, membrane choice, and ionomer type, were also carefully examined to enhance the cell performance. In sharp contrast to prior studies limited to current densities below 20 mA/cm² in bicarbonate-based captured CO2 solutions, this work demonstrates a remarkable current density of 300 mA/cm² with an FE to formate comparable to the case with gas-fed CO2 reduction. Moreover, the process sustained an FE above 50% at a high current density of 500 mA/cm². The DRM-BiNS catalyst exhibited outstanding selectivity, activity, and stability, significantly outperforming oxide-derived bismuth nanosheets (OD-BiNS) in captured CO2 reduction. These findings offer critical insights into the development of sustainable and scalable CO2 utilization technologies. 

Ethylene oxide (EO) is one of the most crucial materials in plastic industries. The traditional catalytic process requires high temperature and pressure to produce EO. A chlorine-assisted system has been reported to produce EO, but it required noble metal catalysts, which significantly increased the cost. In this work, a MOF-derived Co 3 O 4 /nitrogen-doped carbon composite (Co 3 O 4 /NC) prepared through a two-step calcination method exhibited remarkable chlorine evolution reaction (ClER) activity as compared with a commercial RuO 2 catalyst, which can be attributed to the higher specific surface area and lower resistance of its porous structure and nitrogen-doped carbon. Furthermore, the Co 3 O 4 /NC maintained a stable potential and a high faradaic efficiency throughout the 10-hour electrolysis test.