Catalytic Performance of Ni/CeO2/X-ZrO2 (X = Ca, Y) Catalysts in the Aqueous-Phase Reforming of Methanol.

Daniel Goma,Leon Lefferts,Jimmy Faria,Miguel Ángel Cauqui,José Juan Calvino,Juan José Delgado

doi:10.3390/nano9111582

Daniel Goma, Leon Lefferts + Show 4 more

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https://doi.org/10.3390/nano9111582

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Journal: Nanomaterials	Publication Date: Nov 8, 2019
Citations: 36	License type: CC BY 4.0

Affiliation: University of Cádiz, University of Twente

Abstract

In this study, we reported on the effect of promoting Ni/ZrO2 catalysts with Ce, Ca (two different loadings), and Y for the aqueous-phase reforming (APR) of methanol. We mainly focused on the effect of the redox properties of ceria and the basicity provided by calcium or yttrium on the activity and selectivity of Ni in this reaction. A systematic characterization of the catalysts was performed using complementary methods such as XRD, XPS, TPR, CO2-TPD, H2 chemisorption, HAADF-STEM, and EDS-STEM. Our results reveal that the improvement in reducibility derived from the incorporation of Ce did not have a positive impact on catalytic behaviour thus contrasting with the results reported in the literature for other Ce-based catalytic compositions. On the contrary, the available Ni-metallic surface and the presence of weak basic sites derived from Ca incorporation seem to play a major role on the catalytic performance for APR of methanol. The best performance was found for a Ce-free catalyst with a molar Ca content of 4%.

Highlights

The future of the so-called hydrogen economy is linked to the possibility of developing economical clean and sustainable methods for both the production of H2 and its subsequent conversion into energy [1]
Similar results were obtained in the analysis of the catalysts after reaction discarding the occurrence of lixiviation under reaction conditions (Table S1)
The activity order observed for this series was as follows: NiCe4CSZ (68) > NiCe8YSZ (54) > NiCe14CSZ (44) > NiCeZr (40). These results reveal that the improvement in reducibility derived from the incorporation of Ce did not have a direct impact on catalytic behaviour contrasting with the results reported in the literature for other Ce-based catalytic compositions

Summary

Introduction

The future of the so-called hydrogen economy is linked to the possibility of developing economical clean and sustainable methods for both the production of H2 and its subsequent conversion into energy [1]. Some of the applications adapted to this energy model would operate, for example, with electricity generated in a fuel cell powered by in situ produced hydrogen overcoming problems associated with storage, transport, and handling of hydrogen gas [2]. In this sense, methanol derived from biorefinery water fractions can be considered an interesting source of hydrogen, as it is an economic product with a considerable H2 content (13%) and transportable (liquid at room temperature). The CO is converted into CO2 and H2 by the water–gas shift (WGS) reaction, for which H2O dissociation is needed (Equation (2))

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