Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, China.
School of Chemistry and Chemical Engineering, Inner Mongolia University, 235 West University Street, Hohhot 010021, China.
Int J Mol Sci. 2023 Oct 3;24(19):14859. doi: 10.3390/ijms241914859.
Catalytic conversion of biomass-derived ethanol into n-butanol through Guerbet coupling reaction has become one of the key reactions in biomass valorization, thus attracting significant attention recently. Herein, a series of supported Cu catalysts derived from Ni-based hydrotalcite (HT) were prepared and performed in the continuous catalytic conversion of ethanol into butanol. Among the prepared catalysts, Cu/NiAlO shows the best performance in terms of butanol selectivity and catalyst stability, with a sustained ethanol conversion of ~35% and butanol selectivity of 25% in a time-on-stream (TOS) of 110 h at 280 °C. While for the Cu/NiFeO and Cu/NiCoO, obvious catalyst deactivation and/or low butanol selectivity were obtained. Extensive characterization studies of the fresh and spent catalysts, i.e., X-ray diffraction (XRD), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Hydrogen temperature-programmed reduction (H-TPR), reveal that the catalysts' deactivation is mainly caused by the support deconstruction during catalysis, which is highly dependent on the reducibility. Additionally, an appropriate acid-base property is pivotal for enhancing the product selectivity, which is beneficial for the key process of aldol-condensation to produce butanol.
通过 Guerbet 偶联反应将生物质衍生的乙醇转化为正丁醇已成为生物质增值的关键反应之一，因此最近引起了广泛关注。在此，我们制备了一系列负载型 Cu 催化剂，这些催化剂源自 Ni 基水滑石（HT），并在乙醇连续催化转化为正丁醇的过程中进行了测试。在所制备的催化剂中，Cu/NiAlO 在正丁醇选择性和催化剂稳定性方面表现出最佳性能，在 280°C、TOS 为 110 h 的条件下，乙醇转化率约为 35%，正丁醇选择性为 25%。而对于 Cu/NiFeO 和 Cu/NiCoO，催化剂则出现明显的失活和/或低的正丁醇选择性。对新鲜和使用后的催化剂进行了广泛的表征研究，包括 X 射线衍射（XRD）、透射电子显微镜（TEM）、X 射线光电子能谱（XPS）和氢气程序升温还原（H-TPR），结果表明，催化剂的失活主要是由于催化过程中载体的解构引起的，而这高度依赖于催化剂的还原性。此外，适当的酸碱性质对于提高产物选择性至关重要，这有利于生成正丁醇的关键缩合反应。
