Chenxia Xu, Jianhua Lv, Jidong Liu, Bao Guo and Wensong Li
{"title":"Br-doped Ga2O3/MCM-41 catalyzed synthesis of propylene carbonate from carbon dioxide and propylene oxide†","authors":"Chenxia Xu, Jianhua Lv, Jidong Liu, Bao Guo and Wensong Li","doi":"10.1039/D4NJ00369A","DOIUrl":null,"url":null,"abstract":"<p >Ga<small><sub>2</sub></small>O<small><sub>3</sub></small>/MCM-41-<em>x</em> (<em>x</em> = 0.4, 0.5, 0.6) heterogeneous catalysts, each with varying levels of Br doping, were synthesized using mesoporous molecular sieves (MCM-41) as a carrier and employed in the synthesis of propylene carbonate (PC) from propylene oxide (PO) and carbon dioxide (CO<small><sub>2</sub></small>). The reaction was conducted under solvent-free and additive-free conditions. Various techniques were utilized to characterize the catalysts’ chemical composition, morphology, and structure. The effects of varied reaction conditions on PO conversion and PC selectivity using Ga<small><sub>2</sub></small>O<small><sub>3</sub></small>/MCM-41-0.5 catalysts were investigated. Under the reaction conditions of 120 °C, 3.5 MPa, 10 h and catalyst dosage of 2.6 wt%, the PO conversion and PC selectivity reached 99.7% and 99.1%, respectively. The catalytic impact correlates strongly with the doping amounts of Ga<small><sub>2</sub></small>O<small><sub>3</sub></small> and Br, primarily due to the interaction of Ga<small><sub>2</sub></small>O<small><sub>3</sub></small> with the surface of MCM-41, leading to the generation of more basic sites and, consequently, a greater abundance of alkali centers. As a nucleophilic reagent, Br functions synergistically with Ga<small><sub>2</sub></small>O<small><sub>3</sub></small>/MCM-41, augmenting the ring-opening rate of PO and improving the activation ability of CO<small><sub>2</sub></small>. The stability of the catalyst underwent evaluation, revealing a slight decrease in activity after repeated use. The reaction mechanism underlying PC synthesis catalyzed by Ga<small><sub>2</sub></small>O<small><sub>3</sub></small>/MCM-41-0.5 was speculated.</p>","PeriodicalId":95,"journal":{"name":"New Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":2.7000,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"New Journal of Chemistry","FirstCategoryId":"92","ListUrlMain":"https://pubs.rsc.org/en/content/articlelanding/2024/nj/d4nj00369a","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Ga2O3/MCM-41-x (x = 0.4, 0.5, 0.6) heterogeneous catalysts, each with varying levels of Br doping, were synthesized using mesoporous molecular sieves (MCM-41) as a carrier and employed in the synthesis of propylene carbonate (PC) from propylene oxide (PO) and carbon dioxide (CO2). The reaction was conducted under solvent-free and additive-free conditions. Various techniques were utilized to characterize the catalysts’ chemical composition, morphology, and structure. The effects of varied reaction conditions on PO conversion and PC selectivity using Ga2O3/MCM-41-0.5 catalysts were investigated. Under the reaction conditions of 120 °C, 3.5 MPa, 10 h and catalyst dosage of 2.6 wt%, the PO conversion and PC selectivity reached 99.7% and 99.1%, respectively. The catalytic impact correlates strongly with the doping amounts of Ga2O3 and Br, primarily due to the interaction of Ga2O3 with the surface of MCM-41, leading to the generation of more basic sites and, consequently, a greater abundance of alkali centers. As a nucleophilic reagent, Br functions synergistically with Ga2O3/MCM-41, augmenting the ring-opening rate of PO and improving the activation ability of CO2. The stability of the catalyst underwent evaluation, revealing a slight decrease in activity after repeated use. The reaction mechanism underlying PC synthesis catalyzed by Ga2O3/MCM-41-0.5 was speculated.