Department of Materials and Applied Chemistry, College of Science and Technology, College of Science and Technology, Nihon University, 1-8-14, Kanda Surugadai, Chiyoda-ku, Tokyo101-8308, Japan.
ACS Appl Mater Interfaces. 2023 Feb 1;15(4):5109-5117. doi: 10.1021/acsami.2c17560. Epub 2023 Jan 20.
The present study firstly reported porous silica hollow spheres as a host material for recovery of ammonia and carbon dioxide and conversion of the compounds into urea. These compounds were effectively introduced into the hollow spheres from an aqueous solution including ammonium and carbonate ions accompanied with catalytically active copper ions from the analyses of diffuse reflectance infrared Fourier transform (DRIFT) spectra and diffusion reflectance ultraviolet-visible and near-infrared (DR UV-vis-NIR) spectra. The ammonium and carbonate ions were converted into urea in the hollow spheres at 323 K under 0.5 MPa of argon atmosphere from the results of the DRIFT spectra. From the results of nitrogen sorption isotherms and X-ray photoelectron spectra (XPS) spectra, the amount of the generated urea depended on the amount of the introduced ammonium ions and the size distribution of the nanospaces in the hollow spheres. Urea was highly generated in the hollow spheres with a high amount of ammonium ions and well-ordered nanospaces from the reactants at high density.
本研究首次报道了多孔硅质空心球作为一种宿主材料，用于回收氨和二氧化碳，并将这些化合物转化为尿素。通过漫反射红外傅里叶变换光谱（DRIFT）和漫反射紫外可见近红外光谱（DR UV-vis-NIR）的分析，这些化合物可以从包含铵离子和碳酸根离子的水溶液中，以及具有催化活性的铜离子，有效地被引入到空心球中。在 323 K 下、在 0.5 MPa 的氩气气氛中，从 DRIFT 光谱的结果可知，空心球内的铵离子和碳酸根离子被转化为尿素。从氮气吸附等温线和 X 射线光电子能谱（XPS）的结果可以看出，生成的尿素量取决于引入的铵离子量和空心球内纳米空间的尺寸分布。从反应物在高密度下的情况来看，空心球内具有高浓度的铵离子和有序纳米空间时，尿素的生成量很高。
