甲烷作为一种无污染的清洁能源,具有储量丰富、环境友好的特点,因此,发展高效稳定的甲烷氧化催化剂具有十分重要的意义。通过两步浸渍法成功制备了铋掺杂的铂基铈-锆-镧催化剂,并将其应用在甲烷完全氧化反应。通过X射线吸收精细结构(X-r...甲烷作为一种无污染的清洁能源,具有储量丰富、环境友好的特点,因此,发展高效稳定的甲烷氧化催化剂具有十分重要的意义。通过两步浸渍法成功制备了铋掺杂的铂基铈-锆-镧催化剂,并将其应用在甲烷完全氧化反应。通过X射线吸收精细结构(X-ray Absorption Fine Structure,XAFS)表征,铋(Bi)和铂(Pt)之间存在较强的相互作用,促进了Pt物种分散到原子簇和单原子级别。然而,Bi的引入会导致Bi/BiO_(x)原子簇覆盖催化剂表面的Pt物种(单原子和原子簇)和载体表面,阻碍了Pt活性物种以及载体与反应物的接触,从而降低了催化剂在甲烷完全氧化中的活性。通过XAFS指认铂与铋之间强相互作用的存在,这对于今后的双金属催化剂的制备具有一定的指导意义。展开更多
Pt is a catalyst in proton exchange membrane fuel cell （PEMFC）, and its activity will be degraded in the air due to the exist- ence of SOx impurities. On strategy is introducing of Mo into the Pt catalyst because it...Pt is a catalyst in proton exchange membrane fuel cell （PEMFC）, and its activity will be degraded in the air due to the exist- ence of SOx impurities. On strategy is introducing of Mo into the Pt catalyst because it can improve the SOx-tolerance capacity. Based on the aforementioned phenomenon, a density function theory （DFT） study on SOx adsorbed on Pt（111） and PtMo（111） was performed to enhance Pt catalytic activity. The adsorption energy of adsorbed species, the net change, partial density of state （PDOS）, and d-band center were calculated and analyzed comparatively. The results show that the presence of Mo-atom weakens the S-Pt bond strength and reduces the adsorption energies for SO2, S and SO3 on PtMo（111）. Moreover, the Mo atom weakens the effects of SO2 on the PtMo（lll） electronic structure and makes the catalyst maintains its original electronic structure after SO2 adsorption as compared with Pt（111）.展开更多
文摘甲烷作为一种无污染的清洁能源,具有储量丰富、环境友好的特点,因此,发展高效稳定的甲烷氧化催化剂具有十分重要的意义。通过两步浸渍法成功制备了铋掺杂的铂基铈-锆-镧催化剂,并将其应用在甲烷完全氧化反应。通过X射线吸收精细结构(X-ray Absorption Fine Structure,XAFS)表征,铋(Bi)和铂(Pt)之间存在较强的相互作用,促进了Pt物种分散到原子簇和单原子级别。然而,Bi的引入会导致Bi/BiO_(x)原子簇覆盖催化剂表面的Pt物种(单原子和原子簇)和载体表面,阻碍了Pt活性物种以及载体与反应物的接触,从而降低了催化剂在甲烷完全氧化中的活性。通过XAFS指认铂与铋之间强相互作用的存在,这对于今后的双金属催化剂的制备具有一定的指导意义。
基金financially supported by the National Basic Research Program of China (973 Program, 2012CB215500, 2012CB720300)the National Natural Science Foundation of China (51072239, 20936008)the Fundamental Research Funds for the Central Universities (CDJZR-12228802)
文摘Pt is a catalyst in proton exchange membrane fuel cell （PEMFC）, and its activity will be degraded in the air due to the exist- ence of SOx impurities. On strategy is introducing of Mo into the Pt catalyst because it can improve the SOx-tolerance capacity. Based on the aforementioned phenomenon, a density function theory （DFT） study on SOx adsorbed on Pt（111） and PtMo（111） was performed to enhance Pt catalytic activity. The adsorption energy of adsorbed species, the net change, partial density of state （PDOS）, and d-band center were calculated and analyzed comparatively. The results show that the presence of Mo-atom weakens the S-Pt bond strength and reduces the adsorption energies for SO2, S and SO3 on PtMo（111）. Moreover, the Mo atom weakens the effects of SO2 on the PtMo（lll） electronic structure and makes the catalyst maintains its original electronic structure after SO2 adsorption as compared with Pt（111）.
