通过高表面积氧化铈催化乙醇蒸汽重整：氧化铈作为一种内在预重整催化剂的作用外文翻译资料

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Catalytic steam reforming of ethanol over high surface area CeO₂:

The role of CeO₂ as an internal pre-reforming catalyst

通过高表面积氧化铈催化乙醇蒸汽重整：氧化铈作为一种内在预重整催化剂的作用

Abstract

摘要

In the present work, it was found that high surface area ceria (CeO₂(HSA)), synthesized by a surfactant-assisted approach, have useful ethanol steam reforming activity under solid oxide fuel cells (SOFCs) temperatures. The catalyst provides good reforming reactivity and high resistance toward carbon deposition compared to Ni/Al₂O₃ and conventional low surface area ceria (CeO₂(LSA)). Although the hydrogen selectivity at steady state from the ethanol steam reforming over CeO₂(HSA) was lower than Rh/Al₂O₃, the resistance toward carbon deposition of CeO₂(HSA) was considerably higher.

在目前的工作中，发现通过表面活性剂辅助的方式合成的高表面积氧化铈(CeO₂(HSA))，在固体氧化物燃料电池(SOFCs)温度下拥有有效乙醇蒸汽重整活性。与Ni/Al₂O₃和传统低表面积氧化铈(CeO₂(LSA))相比，该催化剂提供了良好的重整反应活性和对碳沉积的高抵抗性。虽然在稳态下，用高表面积氧化铈重整酒精蒸汽时对氢的选择性要比用Rh/Al₂O₃低，但用高表面积氧化铈时对积碳的抵抗性明显更高。

At temperature 900℃, the main products from the steam reforming of ethanol over CeO₂(HSA) (with inlet C₂H₅OH/H₂O molar ratio of 1.0/3.0) were H₂ (with the selectivity of 67.5%), CH₄, CO, and CO₂. In contrast, the formations of C₂H₄ and C₂H₆ were also observed from the steam reforming of ethanol over Ni/AlO₃ and CeO₂(LSA). The combination use of CeO₂ and Ni/Al₂O₃ was studied in an annular ceramic reactor by applying CeO₂ as an internal pre-reforming catalyst. The main purpose of CeO₂ is to convert all ethanol and other high hydrocarbon compounds (e.g. C₂H₄ and C₂H₆) forming CH₄, CO, CO₂, and H₂, while Ni/Al₂O₃ is applied to reform all CH₄ left from the pre-reforming section and maximize the yield of hydrogen production. After operated at 900℃ for 100h, this combination pattern offers high hydrogen selectivity (87.0–91.4%) and good resistance toward carbon deposition. This successful development eliminates the requirement of expensive noble metal catalysts or the installation of an external pre-reformer in order to reform ethanol internally (IIR-SOFC).

在温度900℃下，使用高表面积氧化铈（入口处乙醇/水的摩尔比为1.0/3.0）催化的乙醇蒸汽重整的主要产物为氢气（选择性为67.5%）、甲烷、一氧化碳和二氧化碳。相比之下，使用Ni/AlO₃和低表面积氧化铈催化的乙醇蒸汽重整中也观察到了乙烯和乙烷的形成。通过应用氧化铈作为内部预重整催化剂，在环形陶瓷反应器中研究了氧化铈和Ni/Al₂O₃的组合使用。氧化铈的主要目的是转化所有乙醇和其它高碳氢化合物（例如乙烯和乙烷），形成甲烷、一氧化碳、二氧化碳和氢气，而Ni/Al₂O₃用以重整所有从预重整部分留下的所有甲烷，并使氢产量最大化。在900℃下反应100小时后，这种组合模式提供高的氢选择性（87.0-91.4％）和良好的抗碳沉积性。这种成功的开发消除了昂贵的贵金属催化剂或安装外部预重整器以便在内部重整乙醇（IIR-SOFC）的需要。

1.Introduction

1.引言

Solid oxide fuel cell (SOFC) with an indirect internal reforming operation, called IIR-SOFC, is expected to be an important technology for energy generation in the near future [1]. Regarding this operation,the endothermic reforming reaction takes place at the reformer, which is in close thermal contact with the anode side of fuel cell where the exothermic electrochemical reaction occurs. The aim of this internal reformer unit is to reform and maximize the yield of hydrogen production, which can be generated from several sources such as natural gas, bio-ethanol, coal, biomass, and biogas, and supply this component to the anode side of SOFC.

具有间接内部重整操作的固体氧化物燃料电池（SOFC），称为IIR-SOFC，预期是在不久的将来产生能量的重要技术[1]。关于该操作，吸热重整反应发生在重整器处，其与发生放热电化学反应的燃料电池的阳极侧紧密热接触。该内部重整单元的目的是改进和最大化氢产量的产率，其可以从几种来源例如天然气、生物乙醇、煤、生物质和沼气产生，并将该组分供应到固体氧化物燃料电池的阳极侧。

Regarding the current oil crisis and the short age of fossil fuels, the development of the biomass-based fuels therefore attracts much attention. Among various resources, bio-ethanol is a promising candidate for hydrogen for SOFC, since it is readily produced by renewable resources(e.g.fermentation of biomasses) and has reasonably high hydrogen content [2,3]. The major difficulty to reform ethanol is the deactivation of the reforming catalyst due to the possible carbon deposition from the ethanol decomposition. It has widely been reported that ethanol can homogenously decompose to several hydrocarbon elements (e.g. acetaldehyde, methane, carbon monoxide, carbon dioxide, ethylene, and ethane) without the requirement of catalyst [4]. The formation of ethylene and ethane is the major problem, as these components act as very strong promoters for carbon formation. When ethanol is reformed internally (IIR-SOFC) without any pre-treatments (i.e. installation of a preliminary reforming unit), the carbon formation can be easily formed on the catalyst surface.

由于目前的石油危机和化石燃料的短缺，因此生物基燃料的开发引起了很大的关注。在各种资源中，生物乙醇是用于固体氧化物燃料电池产氢的有前途的候选物，因为其易于由可再生资源（例如生物质的发酵）生产并且具有相当高的氢含量[2,3]。重整乙醇的主要困难在于重整催化剂的失活，这是由于乙醇分解可能产生积碳。乙醇可以均匀分解成几种烃元素（例如乙醛、甲烷、一氧化碳、二氧化碳、乙烯和乙烷）而不需要催化剂[4]，这已被广泛报道。乙烯和乙烷的形成是主要问题，因为这些组分充当了碳形成的非常强的促进剂。当乙醇在没有任何预处理（即安装初步重整单元）的情况下，在内部重整（IIR-SOFC）时，可以容易地在催化剂表面上形成碳。

The approach in this work is developing of an alternative catalytic reforming operation that is enabling to reform ethanol with low degree of carbon deposition at SOFC temperatures, 800–1000℃. The successful development of this operation would eliminate the requirement of the preliminary reforming installation making IIR-SOFC fueled by ethanol more efficient and attractive. Previously, hydrogen production from the reforming of ethanol has been studied by several researchers [5], most of them have investigated the reforming of ethanol over noble metal catalysts (e.g. Rh, Ru, Pt, Pd) on several oxide supports (e.g. Al₂O₃, MgO, SiO₂, TiO₂) [5–11]. Freni et al. [6,7,10] presented that Rh/Al₂O<sub

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