Facile Microwave Synthesis of Hierarchical Porous Copper Oxide and Its Catalytic Activity and Kinetics for Carbon Monoxide Oxidation

Abstract

The synthesis of copper oxide (CuO)-based nanomaterials has received a tremendous deal of interest in recent years. Particularly, the design and development of novel CuO structures with improved physical and chemical properties have attracted immense attention, especially for catalysis applications. We report on a rational, rapid, and surfactant-free microwave synthesis (MWS) of hierarchical porous copper oxide (HP-CuO) with a three-dimensional (3D) sponge-like topology using an MWS reactor. The activity of the microwave (MW)-synthesized HP-CuO catalysts for carbon monoxide (CO) oxidation was studied and compared to CuO prepared by the conventional heating method (CHM). Results showed that HP-CuO catalysts prepared by MWS for 10 and 30 min surpassed the CuO catalyst prepared by CHM, exhibiting T 80 of 98 and 115 °C, respectively, as compared to 185 °C of CuO prepared by CHM (T 80 is the temperature corresponding to 80% CO conversion). In addition, the MW-synthesized HP-CuO catalysts outperformed the CHM-synthesized CuO, achieving a 100% CO conversion at 150 °C compared to 240 °C in the case of CuO prepared by CHM. Interestingly, the HP-CuO catalyst expressed workable CO conversion kinetics with a reaction rate of c.a.35 μmol s −1 g −1 at 150 °C and apparent activation energy (E a ) of 82 kJ mol −1 . The HP-CuO catalyst showed excellent cycling and long-term stabilities for CO oxidation up to 4 cycles and 72 h on the stream, respectively. The enhanced catalytic activity and stability of the HP-CuO catalyst appear to result from the unique topological and structural features of HP-CuO, which were revealed by SEM, XRD, Raman, BET, TGA, XPS, and TPR techniques.

Promotional Effects of Heat Treatments on Pt–CeO2 Nanocatalyst Derived via Hydrothermal Leaching for CO Oxidation

“…Their work particularly emphasized the synthesis of ceria-reduced graphene oxide composites, which exhibited exceptional performance in CO oxidation, surpassing that of stand-alone materials. Another notable advancement was presented by Zedan et al in their exploration of copper oxide (CuO)-based nanomaterials . They demonstrated a unique microwave synthesis approach that yielded hierarchically porous copper oxide with enhanced catalytic properties.…”

“…Another notable advancement was presented by Zedan et al in their exploration of copper oxide (CuO)-based nanomaterials. 33 They demonstrated a unique microwave synthesis approach that yielded hierarchically porous copper oxide with enhanced catalytic properties. These materials showed superior performance in CO oxidation compared with conventionally synthesized CuO.…”

Design, Synthesis, and Diverse Applications of Cu-Based Photocatalysts: A Review

“…Zedan et al. synthesized a new type of 3D spongy porous CuO by a microwave method, which has large porosity and specific surface area, high thermal stability and reducibility . Their work demonstrated that this particular structure has a significant positive effect on catalytic activity.…”

Rational synthesis of gold-ceria catalysts supported on reduced graphene oxide with remarkable activity for CO oxidation

“…Also, CO is one of the undesired and deteriorating impurity gases that can poison catalysts used in some technological applications such as polymer electrolyte membrane fuel cells even at trace levels [4]. Therefore, technological approaches have been introduced for the elimination of CO via direct capture using CO fixation materials [5], electrocatalytic oxidation [6], photocatalytic oxidation [7], and thermochemical catalytic oxidation into carbon dioxide (CO 2 ) [8,9]. The thermochemical catalytic oxidation of highly toxic CO into less toxic CO 2 by using a heterogeneous catalyst is an efficient and reliable technique for the continuous removal of CO in the gas phase [10].…”