Sakr Ayat A-E, Abd El-Hafiz Dalia R, Elgabry Osama, Abdullah Eman S, Ebiad Mohamed A, Zaki Tamer
Gas Chromatogarphy Lab, Analysis & Evaluation Division, Egyptian Petroleum Research Institute Nasr City Cairo 11727 Egypt
Catalysis Lab, Petroleum Refining Division, Egyptian Petroleum Research Institute Nasr City P.B. 11727 Cairo Egypt.
RSC Adv. 2023 Nov 16;13(48):33541-33558. doi: 10.1039/d3ra06190f.
The accumulation of anthropogenic greenhouse gases (GHGs) in the atmosphere causes global warming. Global efforts are carried out to prevent temperature overshooting and limit the increase in the Earth's surface temperature to 1.5 °C. Carbon dioxide and methane are the largest contributors to global warming. We have synthesized copper-aluminium layered double hydroxide (Cu-Al LDH) catalysts by urea hydrolysis under microwave (MW) irradiation. The effect of MW power, urea concentration, and M/M ratios was studied. The physicochemical properties of the prepared LDH catalysts were characterized by several analysis techniques. The results confirmed the formation of the layered structure with the intercalation of urea-derived anions. The urea-derived anions enhanced the optical and photocatalytic properties of the nano Cu-Al LDH in the visible-light region. The photocatalytic activity of the prepared Cu-Al LDH catalysts was tested for greenhouse gas conversion (CH, CO, and HO) under visible light. The dynamic gas mixture flow can pass through the reactor at room temperature under atmospheric pressure. The results show a high conversion percentage for both CO and CH. The highest converted amounts were 7.48 and 1.02 mmol mL g for CH and CO, respectively, under the reaction conditions. The main product was formaldehyde with high selectivity (>99%). The results also show the stability of the catalysts over several cycles. The current work represents a green chemistry approach for efficient photocatalyst synthesis, visible light utilization, and GHGs' conversion into a valuable product.
大气中人为温室气体（GHGs）的积累导致全球变暖。全球正在努力防止温度超调，并将地球表面温度的升高限制在1.5摄氏度以内。二氧化碳和甲烷是全球变暖的最大贡献者。我们通过微波（MW）辐射下的尿素水解合成了铜铝层状双氢氧化物（Cu-Al LDH）催化剂。研究了微波功率、尿素浓度和M/M比的影响。采用多种分析技术对制备的LDH催化剂的物理化学性质进行了表征。结果证实了层状结构的形成以及尿素衍生阴离子的插层。尿素衍生阴离子增强了纳米Cu-Al LDH在可见光区域的光学和光催化性能。在可见光下测试了制备的Cu-Al LDH催化剂对温室气体转化（CH、CO和HO）的光催化活性。动态气体混合物流可以在室温常压下通过反应器。结果表明，CO和CH的转化率都很高。在反应条件下，CH和CO的最高转化量分别为7.48和1.02 mmol mL g。主要产物是选择性高（>99%）的甲醛。结果还表明了催化剂在几个循环中的稳定性。目前的工作代表了一种绿色化学方法，用于高效光催化剂合成、可见光利用以及将温室气体转化为有价值的产品。
