High stability and activity of solution combustion synthesized Pd-based catalysts for methane combustion in presence of water
High stability and activity of solution combustion synthesized Pd-based catalysts for methane combustion in presence of water
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DOI：
10.1016/j.apcatb.2018.02.049
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发表时间：
2018-08
期刊：
影响因子：
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通讯作者：
Alessandra Toso;Sara Colussi;Shiva Padigapaty;C. Leitenburg;A. Trovarelli
中科院分区：
文献类型：
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作者：
Alessandra Toso;Sara Colussi;Shiva Padigapaty;C. Leitenburg;A. Trovarelli
通过溶液燃烧合成（SCS）制备Pd-二氧化铈和Pd-二氧化铈-氧化锆催化剂，并在10体积% H2O存在下测试甲烷氧化。并与传统的浸渍催化剂进行了比较。两个SCS样品表现出更好的稳定性和催化活性的完全恢复后，在723 K的循环湿/干气氛中的延长时间的流相比，IW的。在瞬态起燃实验中，温度的增加，以实现30%的甲烷转化率仅为34 K的Pd/Ce0.75Zr0.25O2SCS。SCS样品的更好的性能归因于其强的Pd-二氧化铈相互作用和其更高的氧交换能力，如通过程序升温还原实验和储氧能力测量所测量的。对于Pd/Ce0.75Zr0.25O2SCS，CO化学吸附、DRIFT和TEM表征揭示了在老化循环后也存在非常小的Pd纳米颗粒，表明在该样品上钯以精细分散的形式存在，其在循环湿/干气氛期间保持稳定。
Pd-ceria and Pd-ceria-zirconia catalysts were prepared by solution combustion synthesis (SCS) and tested for methane oxidation in presence of 10 vol% H2O. Their behavior was compared with that of traditional incipient wetness impregnated catalysts (IW). Both SCS samples showed better stability and complete recovery of catalytic activity after prolonged time-on-stream at 723 K in cycling wet/dry atmosphere compared to IW ones. During transient light-off experiments, the increase in the temperature to achieve 30% methane conversion was of only 34 K for Pd/Ce0.75Zr0.25O2SCS. The better performance of SCS samples has been attributed to their strong Pd-ceria interaction and to their higher oxygen exchange capability, as measured by Temperature Programmed Reduction experiments and oxygen storage capacity measurements. For Pd/Ce0.75Zr0.25O2SCS, CO chemisorption, DRIFT and TEM characterization revealed the presence of very small Pd nanoparticles also after the aging cycle, indicating that on this sample palladium is present in a finely dispersed form that remains stable during cycling wet/dry atmosphere.