Fangkoch Sisira, Boonkum Sutida, Ratchahat Sakhon, Koo-Amornpattana Wanida, Eiad-Ua Apiluck, Kiatkittipong Worapon, Klysubun Wantana, Srifa Atthapon, Faungnawakij Kajornsak, Assabumrungrat Suttichai
Department of Chemical Engineering, Faculty of Engineering, Mahidol University, Nakhon Pathom 73170, Thailand.
College of Nanotechnology, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand.
ACS Omega. 2020 Mar 23;5(12):6956-6966. doi: 10.1021/acsomega.0c00326. eCollection 2020 Mar 31.
In the present work, the solvent-free hydrodeoxygenation of palm oil as a representative triglyceride model compound to diesel-like hydrocarbons was evaluated in a batch reactor using Pt-decorated MoO catalysts. The catalysts with various Pt loadings (0.5-3%) were synthesized by an incipient wetness impregnation method. The metallic Pt and MoO phases were detected in the XRD patterns of as-prepared catalysts after the reaction and acted as active components for the deoxygenation reactions. The XPS experiments confirmed the existence of metallic Pt and PtO species. The XANES investigation of Mo L-edge spectra elucidated a change in the valence state by the transformation of MoO into MoO species after the deoxygenation reaction. The TEM observation revealed the formation of Pt nanoparticles in the range of 1-3 nm decorated on MoO species. The number of acid sites increased with stronger metal-support interactions on increasing the Pt loading. The catalytic performance of the MoO catalyst significantly improved with a small amount of Pt decoration. However, the further increase in Pt loading did not relatively increase the deoxygenation activity due to the formation of the agglomerated Pt particles. The high performance of the decorated catalysts could be attributed to the moderate acidity from the Pt dispersed on MoO toward decarbonylation and decarboxylation reactions.
在本工作中,以棕榈油作为代表性甘油三酯模型化合物,在间歇式反应器中使用负载铂的MoO催化剂对其向类柴油碳氢化合物的无溶剂加氢脱氧反应进行了评估。通过初湿浸渍法合成了具有不同铂负载量(0.5 - 3%)的催化剂。反应后的制备催化剂的XRD图谱中检测到金属铂和MoO相,它们作为脱氧反应的活性成分。XPS实验证实了金属铂和PtO物种的存在。对Mo L边光谱的XANES研究表明,脱氧反应后MoO向MoO物种的转变导致了价态变化。TEM观察显示在MoO物种上装饰有1 - 3 nm范围内的铂纳米颗粒形成。随着铂负载量增加,金属 - 载体相互作用增强,酸位点数量增加。少量铂修饰后,MoO催化剂的催化性能显著提高。然而,由于形成了团聚的铂颗粒,铂负载量的进一步增加并未相对提高脱氧活性。修饰催化剂的高性能可归因于分散在MoO上的铂对脱羰和脱羧反应具有适度的酸度。