Enhanced ceria nanoflakes using graphene oxide as a sacrificial template for CO oxidation and dry reforming of methane
Enhanced ceria nanoflakes using graphene oxide as a sacrificial template for CO oxidation and dry reforming of methane
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DOI：
10.1016/j.apcatb.2018.10.011
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发表时间：
2019-03
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影响因子：
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通讯作者：
Shawn C. Rood;Huseyin Ahmet;Anais Gomez-Ramon;L. Torrente‐Murciano;T. Reina;Salvador Eslava
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文献类型：
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作者：
Shawn C. Rood;Huseyin Ahmet;Anais Gomez-Ramon;L. Torrente‐Murciano;T. Reina;Salvador Eslava
开发新的制造方法来生产具有良好高温稳定性的二氧化铈催化剂对于它们在一系列不同应用中的实施至关重要。在本文中，氧化石墨烯薄片在二氧化铈颗粒的合成中用作牺牲模板以复制氧化石墨烯的二维性。虽然在没有氧化石墨烯的情况下进行合成导致二氧化铈微晶的大附聚，但在合成期间添加氧化石墨烯导致二氧化铈纳米片（<10 nm）复制氧化石墨烯形态。这种新颖的形状限制了原子在高温下向二维平面的扩散，这转化为低烧结度，从而增强了热稳定性。以这种方式，二氧化铈薄片能够在高温（>400 °C）下煅烧后保持高表面积，这导致一氧化碳氧化的催化性能改善。当二氧化铈薄片用作镍颗粒的催化载体时，这种抵抗烧结的能力也具有有益的效果。改进的金属分散和高的金属-载体相互作用导致在甲烷的干重整期间比类似制备的未模板化的二氧化铈镍催化剂更低的烧结。这些结果证明了使用氧化石墨烯作为牺牲模板用于生产在高温下具有良好催化性能的耐烧结催化剂的优点。
The development of novel fabrication methods to produce ceria catalysts with good high-temperature stability is critical for their implementation across a range of different applications. Herein, graphene oxide flakes are used as a sacrificial template in the synthesis of ceria particles to replicate the graphene oxide’s two-dimensionality. While performing the synthesis without graphene oxide results in large agglomerations of ceria crystallites, the addition of graphene oxide during the synthesis results in ceria nanoflakes (<10 nm) replicating the graphene oxide morphology. This novel shape limits the diffusion of atoms at high temperature to a two-dimensional plane which is translated into a low sintering degree and consequently, an enhanced thermal stability. In this way, the ceria flakes are capable of maintaining high surface areas after calcination at high temperatures (>400 °C) which results in improved catalytic performance for the oxidation of carbon monoxide. This resistance versus sintering has also a beneficial effect when ceria flakes are used as catalytic support of nickel particles. Improved metal dispersion and high metal-support interaction leads to lower sintering during the dry reforming of methane than similarly prepared un-templated ceria nickel catalysts. These results demonstrate the advantage of using graphene oxide as a sacrificial template for the production of sintering-resistant catalysts with good catalytic performance at high temperatures.