Aqueous-phase reforming of xylitol over Pt/C and Pt/TiC-CDC catalysts: catalyst characterization and catalytic performance

The high cost of Pt based catalyst for aqueous phase reforming (APR) reaction makes it advantageous to develop less cost of other metals for the same reaction. APR is hydrogen production process from biomass-derived source at mild condition near 500 K and firstly reported by Dumesic and co-worker. The use of hydrogen as environmentally friendly energy carrier has been massively encouraged over the last year. When hydrogen is used in fuel cell for power generation, it produces a little or no pollutants. The aim of this study is to study the effect of some precious metal catalysts for APR process. Due to investigation of metal catalysts for APR process, four precious metals (Cu, Co, Zn, Ni) supported on γ-Al2O3 with 20% feeding amount have been successfully prepared by impregnation method. Those precious metals were identified as promising catalysts for APR. The catalysts were characterized by N2 physisorption at 77 K, X-Ray Diffraction (XRD) and Fourier Transform-Infra Red (FT-IR). The catalytic performance was investigated at 523 K and autogenous pressure in a batch reactor with glycerol concentration of 10%. The gaseous hydrogen product was observed over the prepared catalysts by GC. It was found that performance of catalysts to yield the hydrogen product was summarized as follow Cu/γ-Al2O3 > Co/γ-Al2O3 > Zn/γ-Al2O3 > Ni/γ-Al2O3.

Download Full-text

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

Nanomaterials ◽

10.3390/nano9111582 ◽

2019 ◽

Vol 9 (11) ◽

pp. 1582 ◽

Cited By ~ 3

Author(s):

Daniel Goma ◽

Juan José Delgado ◽

Leon Lefferts ◽

Jimmy Faria ◽

José Juan Calvino ◽

...

Keyword(s):

Aqueous Phase ◽

Positive Impact ◽

Catalytic Performance ◽

Redox Properties ◽

Metallic Surface ◽

Aqueous Phase Reforming ◽

Basic Sites ◽

H2 Chemisorption ◽

Catalytic Behaviour

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%.

Download Full-text

Evaluating the Activity and Stability of Perovskite LaMO3-Based Pt Catalysts in the Aqueous Phase Reforming of Glycerol

Topics in Catalysis ◽

10.1007/s11244-021-01449-6 ◽

2021 ◽

Author(s):

Donald R. Inns ◽

Alexander J. Mayer ◽

Vainius Skukauskas ◽

Thomas E. Davies ◽

June Callison ◽

...

Keyword(s):

Phase Separation ◽

Aqueous Phase ◽

Supported Catalysts ◽

Sol Gel ◽

Catalytic Performance ◽

Significant Loss ◽

Particle Migration ◽

Support Surface ◽

Aqueous Phase Reforming ◽

Surface Areas

AbstractThe aqueous phase reforming of glycerol, to hydrogen, alkanes and liquid phase dehydration/dehydrogenation products, was studied over a series of 1 wt% Pt/LaMO3 (where M = Al, Cr, Mn, Fe, Co, Ni) catalysts and compared to a standard 1 wt% Pt/γ-Al2O3 catalyst. The sol–gel combustion synthesis of lanthanum-based perovskites LaMO3 produced pure phase perovskites with surface areas of 8–18 m2g−1. Glycerol conversions were higher than the Pt/γ-Al2O3 (10%) for several perovskite supported catalysts, with the highest being for Pt/LaNiO3 (19%). Perovskite-based catalysts showed reduced alkane formation and significantly increased lactic acid formation compared to the standard catalyst. However, most of the perovskite materials undergo phase separation to LaCO3OH and respective M site oxides with Pt particle migration. The exception being the LaCrO3 support which was found to remain structurally stable. Catalytic performance remained stable over several cycles, for catalysts M = Al, Cr and Ni, despite phase separation of some of these materials. Materials where M site leaching into solution was observed (M = Mn and Co), were found to be catalytically unstable, which was hypothesised to be due to significant loss in support surface area and uncontrolled migration of Pt to the remaining support surface. In the case of Pt/LaNiO3 alloying between the exsoluted Ni and Pt was observed post reaction.

Download Full-text