Regeneration study of Ni/hydroxyapatite spent catalyst from dry reforming
Regeneration study of Ni/hydroxyapatite spent catalyst from dry reforming
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DOI：
10.1016/j.cattod.2017.05.092
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发表时间：
2017-06
期刊：
影响因子：
5.3
通讯作者：
B. Vasconcelos;D. Minh;P. Sharrock;A. Nzihou
中科院分区：
文献类型：
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作者：
B. Vasconcelos;D. Minh;P. Sharrock;A. Nzihou
研究了甲烷干重整反应用镍基羟基磷灰石基催化剂（Ni/Ca-HA 1_S）的再生。进行三次连续的DRM/再生循环。对再生步骤测试两种不同的气化剂：空气和二氧化碳（21%C02/N2）。目的是评价催化剂在不同气氛下的再生能力。再生在700 °C下在70 mL/min的气化剂下原位进行。在两种测试气氛的每个循环之间获得可再现的结果，并且仅注意到小的不可逆失活。几个表征（SEM，TEM，TPR，XRD）的新鲜和废催化剂允许证明，不可逆的失活引起的致密化的镍颗粒和核-壳碳的形成。尽管反应物的转化率略有降低，但在两种气氛下的DRM/再生的三个循环期间，合成气的选择性为约80-90%，并且没有观察到选择性的变化。结果表明，Ni/Ca-HA_（1_S）催化剂在不同气氛下均能很好地再生，具有较好的甲烷干重整反应性能。
In the present work, the regeneration of a spent nickel hydroxyapatite-based catalyst (Ni/Ca-HA1_S) used in dry reforming of methane (DRM) was investigated. Three successive cycles of DRM/regeneration were performed. Two different gasifying agents were tested for the regeneration step: air and carbon dioxide (21%CO2/N2). The aim was to evaluate the ability of regeneration of the catalyst under different atmospheres. The regeneration was performedin situat 700 °C under 70 mL/min of gasifying agent. Reproducible results were obtained between each cycle for the two atmospheres tested and only a small irreversible deactivation was noticed. Several characterizations (SEM, TEM, TPR, XRD) of the fresh and spent catalysts allowed proving that the irreversible deactivation was provoked by densification of nickel particles and core-shell carbon formation. Despite the slight decrease in reactants’ conversions, selectivity to syngas was around 80–90% during the three cycles of DRM/regeneration with both atmospheres and no changes in the selectivity were observed. The results proved that the Ni/Ca-HA1_S catalyst could be easily regenerated under different atmospheres and make it competitive for dry reforming of methane.