2023-09-11 ノースウェスタン大学
◆このプロセスは水処理施設に利益をもたらし、炭素排出を削減し、収益を生み出す可能性があります。しかし、商業化にはまだ課題が残っており、水処理の文脈での不純物の処理とプロセスの効率向上が必要です。
＜関連情報＞
- https://news.northwestern.edu/stories/2023/09/hybrid-catalyst-produces-critical-fertilizer-and-cleans-wastewater/
- https://www.nature.com/articles/s41929-023-01020-4
ハイブリッド触媒を用いたリレー触媒反応により、硝酸塩とCO2から尿素を選択的に電気化学合成 Selective electrochemical synthesis of urea from nitrate and CO2 via relay catalysis on hybrid catalysts
Yuting Luo,Ke Xie,Pengfei Ou,Chayse Lavallais,Tao Peng,Zhu Chen,Zhiyuan Zhang,Ning Wang,Xiao-Yan Li,Ivan Grigioni,Bilu Liu,David Sinton,Jennifer B. Dunn & Edward H. Sargent
Nature Catalysis Published:11 September 2023
DOI:https://doi.org/10.1038/s41929-023-01020-4
Abstract
The nitrogen cycle needed for scaled agriculture relies on energy- and carbon-intensive processes and generates nitrate-containing wastewater. Here we focus on an alternative approach—the electrified co-electrolysis of nitrate and CO2 to synthesize urea. When this is applied to industrial wastewater or agricultural runoff, the approach has the potential to enable low-carbon-intensity urea production while simultaneously providing wastewater denitrification. We report a strategy that increases selectivity to urea using a hybrid catalyst: two classes of site independently stabilize the key intermediates needed in urea formation, *CO2NO2 and *COOHNH2, via a relay catalysis mechanism. A Faradaic efficiency of 75% at wastewater-level nitrate concentrations (1,000 ppm NO3− [N]) is achieved on Zn/Cu catalysts. The resultant catalysts show a urea production rate of 16 µmol h−1 cm−2. Life-cycle assessment indicates greenhouse gas emissions of 0.28 kg CO2e per kg urea for the electrochemical route, compared to 1.8 kg CO2e kg−1 for the present-day route.
