Enhanced oxygen mobility and reactivity for ethanol steam reforming

Abstract

This article describes a strategy for increasing oxygen storage capacity (OSC) of ethanol steam reforming (ESR) catalysts. Sintering and carbon deposition are major defects of nickel-based catalysts for ESR; tuning oxygen mobility (OM) of CeO 2 -based supports can overcome these drawbacks and promote H 2 production. We have successfully increased OSC and OM by adding Mg into the lattice of Ni/CeO 2 to promote H 2 production in ESR. The insertion of Mg into the CeO 2 lattice efficiently promotes the reduction of Ce 4þ according to X-ray powder diffraction (XRD) and temperature-programmed reduction (TPR) analysis. Mg-modified Ni/CeO 2 catalysts have larger OSC and smaller nickel crystallite size compared with bare Ni/CeO 2 . The optimal Mg addition is 7 mol % (Ni/7MgCe) with the best OM. We also present evidence indicating that Mg addition significantly promotes ethanol conversion and H 2 production in ESR, and that Ni/7MgCe yields the best performance due to the high OM of the support. These Mg-modified catalysts also produce less carbon deposition compared with Ni/ CeO 2 , and the amount of deposited carbon decreases with increasing Mg addition. Ni/ 7MgCe has the best resistance to carbon deposition owing to the excellent OM.

Catalytic oxidation of volatile organic compounds (n-hexane, benzene, toluene, o-xylene) promoted by cobalt catalysts supported on γ-Al2O3-CeO2

“…The oxygen storage capacity (OSC) was calculated based on oxygen uptake. These values allow us to estimate the total amount of oxygen available in the oxide catalyst (Zhang et al, 2012). The Co 20 /γ-Al 2 O 3 -CeO 2 catalyst has a larger OSC than the Co 10 /γ-Al 2 O 3 -CeO 2 catalyst, indicating that the former has a higher amount of oxygen vacancies, as also observed from the N 2 physisorption results.…”

Hydrogen Production by Ethanol Steam Reforming (ESR) over CeO2 Supported Transition Metal (Fe, Co, Ni, Cu) Catalysts: Insight into the Structure-Activity Relationship

“…Ceria has been widely employed in several catalytic reactions, involving the WGS reaction [28], NOx reduction [29,30], oxidation or partial oxidation of hydrocarbons [31], steam reforming [32], etc., owing to its excellent redox properties. The mobile oxygen related to the ceria lattice, is considered to be responsible for the oxidation of deposited carbonaceous fragments, thus protecting the catalyst surface from poisoning [33][34][35][36]. In addition, mobile oxygen can activate water, with regard to the formation of hydroxyl groups, resulting in higher ESR efficiency [25,33].…”

“…The mobile oxygen related to the ceria lattice, is considered to be responsible for the oxidation of deposited carbonaceous fragments, thus protecting the catalyst surface from poisoning [33][34][35][36]. In addition, mobile oxygen can activate water, with regard to the formation of hydroxyl groups, resulting in higher ESR efficiency [25,33]. In a comprehensive study by Xu et al [25], utilizing both in situ and ex situ characterization techniques it was revealed that metallic Ni and Ce(III) entities were the active components under ESR conditions.…”

Hydrogen via steam reforming of liquid biofeedstock

“…A high oxygen mobility (redox property), high oxygen storage capacity, strong interaction with the supported metal (strong metal-support interaction) and their ease of modification promoted several investigations of hydrogen production by SRE over CeO 2 supported catalysts [27][28][29]. Fajardo et al [30] performed SRE with S/EtOH of 3 at 673 K over Ni supported over CeO 2 catalyst prepared by using a biopolymer polymerization method.…”