Dolomite-Derived Ni-Based Catalysts with Fe Modification for Hydrogen Production via Auto-Thermal Reforming of Acetic Acid

Abstract

Bio-oil can be obtained via fast pyrolysis of biomass, and typically contains acetic acid (~30 mass %). The acetic acid has often been tested as a model compound for hydrogen production via reforming bio-oil, in which catalysts are a key factor for stable hydrogen production. However, deactivation of catalysts by coking and oxidation hinders the application of the reforming process. Dolomite-derived Ni-based catalysts with Fe additive, MgNi 0.2 Ca 0.8´x Fe x O 2˘δ (x = 0-0.8), were successfully synthesized by the hydrothermal synthesis method, and then tested in auto-thermal reforming (ATR) of acetic acid (AC). The MgNi 0.2 Ca 0.5 Fe 0.3 O 2˘δ catalyst performed a stable reactivity in ATR: the conversion of AC reached 100%, and the H 2 yield remained stable around 2.6 mol-H 2 /mol-AC. The catalysts were characterized by X-ray diffraction (XRD), N 2 physisorption, X-ray photoelectron spectra (XPS), H 2 -temperature-programmed reduction (TPR), inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and Thermogravimetry (TG); the results show that a periclase-like solid solution of Mg(Ni,Fe)O and lime were formed via the precursors of dolomite and hydrotalcite, and then transformed into Fe-rich Ni-Fe alloy with basic support of MgO-CaO after reduction. The stable Ni 0 spices with basic support can explain the stability and resistance to coking during ATR of AC.

Zn‐Al hydrotalcite‐derived Co x Zn y AlO z catalysts for hydrogen generation by auto‐thermal reforming of acetic acid

“…With the high surface area of alumina, dispersion of the active component can be effectively increased, and active sites for adsorption and activation of reactant can be supplied . However, in the harsh atmosphere of ATR with O 2 in the feed and relatively high reacting temperature, deactivation by oxidation, sintering, and coking within the cobalt/alumina catalysts can be found . ZnO was reported as structure modifier and electron donor in Zn‐Ni‐Al‐O catalysts and shows potential to address the deactivation concern for a Zn‐/Al‐derived catalyst.…”

“…9 However, in the harsh atmosphere of ATR with O 2 in the feed and relatively high reacting temperature, deactivation by oxidation, sintering, and coking within the cobalt/alumina catalysts can be found. 10,11 ZnO was reported as structure modifier and electron donor in Zn-Ni-Al-O catalysts and shows potential to address the deactivation concern for a Zn-/Al-derived catalyst. Oxidation and coking can be constrained because of (a) electron donation with Zn to the surface active metal and (b) mobile oxygen spilled over from ZnO.…”

Performance of an Auto-Reduced Nickel Catalyst for Auto-Thermal Reforming of Dodecane

“…The performances of Ni-based monolith reforming catalysts for the SR, POx, and ATR of n-dodecane have also been evaluated [14][15][16]. In particular, the catalytic properties and carbon-decomposition resistance of nickel-alumina catalysts have been studied in the SR reactions of various hydrocarbon fuels [17][18][19][20][21]. Nickel-alumina-based catalysts are usually prepared by impregnation or co-precipitation, with the former method being simpler than the latter.…”

Hydrogen Production from Cyclic Chemical Looping Steam Methane Reforming over Yttrium Promoted Ni/SBA-16 Oxygen Carrier

“…Also, they have wide availability and low cost compared to noble metal materials [25,26]. However, Ni-based systems generally suffer from severe deactivation caused by coke deposition and/or thermal sintering of the metallic phases due to their low tammann temperature (863 K) [27][28][29]. Therefore, some approaches have been applied in order to enhance the catalytic performance and durability of nickel-based materials in reforming reactions.…”