STTR Phase II: Scalable CO2 electrolyzers for the competitive carbon negative production of formic acid

这个小型企业技术转让（STTR）二期项目的更广泛影响是开发直接利用二氧化碳和电力的电催化甲酸生产工艺。这一过程将在生产甲酸的同时减少温室气体排放，甲酸目前用于农业青贮保鲜、皮革鞣制和化学工业。经济分析预测，这种电催化工艺目前可以与目前市场上的油气衍生甲酸竞争。此外，这一过程有可能实现净负温室气体排放，这意味着它将消耗二氧化碳以生产有价值的化学产品。直接的应用包括利用来自生物乙醇生产、热解厂、垃圾填埋气、采用碳捕获技术的发电厂等的废弃二氧化碳。在可再生能源的低温过程中，以二氧化碳为原料生产甲酸预计将抵消相当于约100万吨的二氧化碳排放，但随着未来运输和能源储存市场的进一步发展，二氧化碳的影响可能达到千兆吨规模。该STTR二期项目开发了一种低能耗电解槽，用于在电力而不是热能驱动的过程中利用二氧化碳。该电解槽将二氧化碳和水的阴极还原制甲酸与阳极水氧化相结合。甲酸是一种主要的商品化学品，用于农业、皮革处理和环境友好型道路除冰。未来的市场包括将其用作液氢储存介质。从二氧化碳中电合成碳产品通常受到低电力和过程能源效率的困扰，这阻碍了商业发展。磷化镍催化剂类显示出克服这些障碍的高潜力。电化学技术的商业应用需要比目前研究表明的反应速度大三个数量级，并结合高能效和产品选择性。这些目标只能通过改善催化剂动力学和优化电解槽的质量传输来实现。这项开发工作面临的挑战是，在商业二氧化碳减排应用中，将该工艺应用于高电流密度和连续操作，同时最大限度地减少竞争性的氢气生成反应。最后，本项目开发的电解槽设计原则适用于许多碳产品的催化剂家族，并有望进一步推动二氧化碳电解槽领域的更广泛发展。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The broader impact of this Small Business Technology Transfer (STTR) Phase II project is the development of an electrocatalytic formic acid production process directly from carbon dioxide (CO2) and electricity. This process will mitigate greenhouse gas emissions while producing formic acid, currently used in agriculture for silage preservation, leather tanning, and the chemical industry. The economic analysis projects that such an electrocatalytic process can currently compete with oil/gas-derived formic acid in the current market. Furthermore, this process has the potential to achieve net negative greenhouse gas emissions, meaning it will consume carbon dioxide in order to produce valuable chemical products. Immediate applications include using waste CO2 from sources such as bio-ethanol production, pyrolysis plants, landfill gas, power plants with carbon capture technology, etc. Formic acid production from CO2 feedstock in a renewable-powered, low-temperature process is expected to offset CO2 emissions equivalent to ~1 million tons, but with future further transportation and energy storage markets, the CO2 impact can reach the gigaton scale.This STTR Phase II project develops a low-energy consumption electrolyzer for CO2 utilization in a process powered by electricity rather than heat. The electrolyzer combines the cathodic reduction of CO2 and water to formic acid with anodic water oxidation. Formic acid is a major commodity chemical used in agriculture, leather treatment, and environmentally-friendly deicing of roadways. Future markets include its use as a liquid hydrogen storage media. Electrosynthesis of carbon products from CO2 has generally been plagued with low electrical and process energy efficiencies that have prevented commercial development. The nickel phosphide catalyst class demonstrates a high potential to overcome these obstacles. Commercial application of electrochemical technologies require reaction rates three orders of magnitude larger than current research studies have shown, combined with high energy efficiencies and product selectivities. These goals can only be achieved by improving catalyst kinetics and optimizing the electrolyzer's mass transport. This development effort takes on the challenge of taking this process to high current densities and continuous operation in commercial CO2 reduction applications while minimizing the competing hydrogen formation reaction. Lastly, the electrolyzer design principles developed in this project are universal to this family of catalysts across many carbon products and are expected to further the field of carbon dioxide electrolyzer development more broadly.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.