Production of Hydrogen by Steam Reforming of Ethanol over Pd-Promoted Ni/SiO 2 Catalyst

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Production of Hydrogen by Steam Reforming of Ethanol over Pd‑Promoted Ni/SiO2 Catalyst Carlos Alberto Chagas1 · Robinson Luciano Manfro1 · Fabio Souza Toniolo2 Received: 9 March 2020 / Accepted: 7 May 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020

Abstract  This study investigated the influence of palladium on the catalytic performance of Ni/SiO2 obtained by incipient wetness impregnation method. Ni/SiO2 and Pd–Ni/SiO2 catalysts were tested in the steam reforming of ethanol for hydrogen production. X-ray diffraction, X-ray fluorescence spectroscopy, ­N2 adsorption–desorption, temperature programmed reduction with hydrogen ­(H2-TPR) and X-ray photoelectron spectroscopy were used to characterize the catalysts in detail. The incorporation of small amount of palladium into Ni/SiO2 catalyst shifts the reduction of Ni species towards lower temperatures. All catalysts displayed total ethanol conversion and high ­H2 selectivity (~ 60%) above 500 °C. Compared to other Ni-based catalysts reported in the recent literature, the catalysts here investigated show promising potential for further application in the hydrogen production by ethanol steam reforming, but CO selectivity should be decreased for fuel cell applications. Graphic Abstract Production of hydrogen by steam reforming of ethanol over Pd-promoted Ni/SiO2 catalyst

EtOH

H2

H2O Catalytic Ethanol Steam Reforming

Ni

Pd

Ni

SiO2 Keywords  Nickel · Palladium · Promoters · Hydrogen · Ethanol

1 Introduction Electronic supplementary material  The online version of this article (https​://doi.org/10.1007/s1056​2-020-03257​-1) contains supplementary material, which is available to authorized users. * Fabio Souza Toniolo [email protected] 1



School of Chemistry—Federal University of Rio de Janeiro, P.O. BOX 68542, Rio de Janeiro 21941‑909, Brazil



Chemical Engineering Program of COPPE—Federal University of Rio de Janeiro, P.O. BOX 68502, Rio de Janeiro 21941‑914, Brazil

2

E t h a n o l st e a m re fo r m i n g ( E S R ) re a c t i o n ­(C2H5OH + 3H2O → 6H2 + 2CO2) using an appropriate catalyst is an efficient route for renewable hydrogen production and has been highlighted in the literature [1–6]. In addition, ethanol is atmospheric carbon neutral since the amount of ­CO2 produced by steam reforming is consumed by the biomass growth, and this offers a nearly closed carbon loop not contributing to the greenhouse gas emissions [7, 8]. The selection and development of a suitable catalyst for ESR is a

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key aspect, once the catalyst must be stable, active, selective, and maximize hydrogen production while simultaneously avoiding the formation of byproducts (CO and C ­ H4). Coke formation is a major issue in the ESR, which may lead to a decrease in catalytic activity and selectivity towards hydrogen, as well as to catalyst deactivation, limiting the industrial application [9, 10]. Carbon formation on the catalyst surface may take place via several reactions, such as ethanol dehydration to ethylene, followed b