{"title":"K-promoted Pt/meso-Al2O3 catalysts for H2 production from dehydrogenation of dodecahydro‑N‑ethylcarbazole","authors":"","doi":"10.1016/j.ces.2024.120764","DOIUrl":null,"url":null,"abstract":"<div><div><em>N</em>-ethylcarbazole, as a liquid organic hydrogen carrier, has shown great promise in the field of hydrogen storage technology. The development of efficient and stable catalyst for producing H<sub>2</sub> through <em>N</em>-ethylcarbazole dehydrogenation is crucial for its practical application. In this study, a series of mesoporous Al<sub>2</sub>O<sub>3</sub>-supported Pt catalysts with K modification were developed for <em>N</em>-ethylcarbazole dehydrogenation. These catalysts were characterization using various techniques including XRD, N<sub>2</sub> adsorption–desorption, TEM, <sup>27</sup>Al MAS NMR, XPS, NH<sub>3</sub>-TPD, H<sub>2</sub>-TPR, CO-FTIR, and Py-IR, providing detailed structural information to elucidate the structure–activity relationship. Mesoporous Al<sub>2</sub>O<sub>3</sub> was found to possess significant amounts of coordinatively unsaturated pentacoordinate Al<sup>3+</sup>, which greatly promotes the dispersion of Pt species for the formation of small Pt particles. The addition of K was observed to modulate the electronic structure of Pt, reduce the acidity of the catalysts, and inhibit the sintering of Pt. These synergetic effects led to Pt<sub>3.0</sub>/K<sub>3.0</sub>-Al<sub>2</sub>O<sub>3</sub>-m achieving remarkable performance in dodecahydro-<em>N</em>-ethylcarbazole dehydrogenation at 180 °C and 101 kPa, delivering a dodecahydro-<em>N</em>-ethylcarbazole conversion of 100 %, H<sub>2</sub> release amount of 5.63 wt% and dehydrogenation efficiency of 97.10 %. Additionally, this catalyst demonstrated high efficiency in the dehydrogenation of dodecahydro-<em>N</em>-propylcarbazole, octahydro-2-methylindole, and octahydro-1,2-dimethylindole, achieving dehydrogenation efficiencies of 99.60 %, 100 % and 100 %, respectively. These findings provide valuable knowledge for the rational design of efficient metal-based catalysts for liquid organic hydrogen carriers in hydrogen storage systems.</div></div>","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":null,"pages":null},"PeriodicalIF":4.1000,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemical Engineering Science","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0009250924010649","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
引用次数: 0
Abstract
N-ethylcarbazole, as a liquid organic hydrogen carrier, has shown great promise in the field of hydrogen storage technology. The development of efficient and stable catalyst for producing H2 through N-ethylcarbazole dehydrogenation is crucial for its practical application. In this study, a series of mesoporous Al2O3-supported Pt catalysts with K modification were developed for N-ethylcarbazole dehydrogenation. These catalysts were characterization using various techniques including XRD, N2 adsorption–desorption, TEM, 27Al MAS NMR, XPS, NH3-TPD, H2-TPR, CO-FTIR, and Py-IR, providing detailed structural information to elucidate the structure–activity relationship. Mesoporous Al2O3 was found to possess significant amounts of coordinatively unsaturated pentacoordinate Al3+, which greatly promotes the dispersion of Pt species for the formation of small Pt particles. The addition of K was observed to modulate the electronic structure of Pt, reduce the acidity of the catalysts, and inhibit the sintering of Pt. These synergetic effects led to Pt3.0/K3.0-Al2O3-m achieving remarkable performance in dodecahydro-N-ethylcarbazole dehydrogenation at 180 °C and 101 kPa, delivering a dodecahydro-N-ethylcarbazole conversion of 100 %, H2 release amount of 5.63 wt% and dehydrogenation efficiency of 97.10 %. Additionally, this catalyst demonstrated high efficiency in the dehydrogenation of dodecahydro-N-propylcarbazole, octahydro-2-methylindole, and octahydro-1,2-dimethylindole, achieving dehydrogenation efficiencies of 99.60 %, 100 % and 100 %, respectively. These findings provide valuable knowledge for the rational design of efficient metal-based catalysts for liquid organic hydrogen carriers in hydrogen storage systems.
期刊介绍:
Chemical engineering enables the transformation of natural resources and energy into useful products for society. It draws on and applies natural sciences, mathematics and economics, and has developed fundamental engineering science that underpins the discipline.
Chemical Engineering Science (CES) has been publishing papers on the fundamentals of chemical engineering since 1951. CES is the platform where the most significant advances in the discipline have ever since been published. Chemical Engineering Science has accompanied and sustained chemical engineering through its development into the vibrant and broad scientific discipline it is today.