分會(huì)

第二十分會(huì)：固體表界面化學(xué)與多相催化

摘要

具有協(xié)同效應(yīng)的PtRu/MCM-41雙金屬催化劑在無(wú)堿條件下的甘油氧化性能研究 閆昊，周鑫，劉熠斌，楊朝合*， 1中國(guó)石油大學(xué)（華東） 重質(zhì)油國(guó)家重點(diǎn)實(shí)驗(yàn)室，山東青島，266580 *Email: yangch@upc.edu.cn 將廉價(jià)的甘油（生物柴油副產(chǎn)物）轉(zhuǎn)化為高附加值的羧酸產(chǎn)物具有重要的意義。在本研究中首次報(bào)道了以O(shè)2為氧化劑，在無(wú)堿介質(zhì)中用雙金屬PtRu催化劑氧化甘油制備甘油酸；結(jié)合密度泛函理論（DFT）計(jì)算和多種表征（如H2-TPR、HAADF-STEM和XPS）發(fā)現(xiàn)，Pt和Ru之間的強(qiáng)相互作用可以促進(jìn)PtRu合金納米粒子的分散，增強(qiáng)金屬表面的電子耦合效應(yīng)。同時(shí)，與單金屬鉑催化劑相比，Ru的引入有助于分子氧和水直接解離成羥基，從而獲得優(yōu)異的催化活性。系統(tǒng)地建立了Ru/Pt比值、催化性能、結(jié)構(gòu)靈敏度和電子耦合效應(yīng)之間的“火山型曲線關(guān)系”。此外，還詳細(xì)分析了結(jié)構(gòu)敏感性和電子耦合效應(yīng)對(duì)不同Ru/Pt比PtRu催化劑催化活性的影響。最后，Pt0.8Ru0.8/MCM-41催化劑在優(yōu)化條件下（80℃、1 MPa O2和12h）表現(xiàn)出良好的催化活性（TOF: 823.9h-1）、甘油酸選擇性（80.1%）和穩(wěn)定性（循環(huán)使用5次）。本文所提出的見(jiàn)解和方法可為雙金屬催化劑在溫和條件下高效轉(zhuǎn)化生物衍生底物的合理設(shè)計(jì)鋪平道路。 圖1. Pt0.8Ru0.8/MCM-41催化劑上的甘油氧化反應(yīng)機(jī)理 關(guān)鍵詞：甘油氧化；PtRu；MCM-41；理論計(jì)算 參考文獻(xiàn) [1]Yan H, Yao S, Yin B, et al. Appl. Catal., B 2019, 259: 118070. Synergistic effects of bimetallic PtRu/MCM-41 nanocatalysts for glycerol oxidation in base-free medium Hao Yan, Xin Zhou , Yibin Liu, Chaohe Yang,* State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Qingdao 266580, China It is of great significance to transform cheap glycerol (biodiesel by-product) into high value added carboxylic acid. Herein, bimetallic PtRu catalyst was first reported for oxidation of glycerol to glyceric acid in base-free medium using O2 as the oxidant. A combination of density functional theory (DFT) calculations and multi-characterizations (e.g., H2-TPR, HAADF-STEM and XPS) revealed that the strong interaction between Pt and Ru could promote the dispersion of PtRu alloy nanoparticles and enhance the electronic coupling effect on the metal surface. Meanwhile, compared to the monometallic Pt catalyst, the introduction of Ru contributes to the direct dissociation of molecular oxygen and water to hydroxyl group, leading to the excellent catalytic activity. A volcanic-shaped relationship between Ru/Pt ratio, catalytic performance, structure-sensitivity and electronic coupling effect was systematically established. Furthermore, the role of structure-sensitivity and electronic coupling effect for the enhanced catalytic activity of PtRu catalysts with different Ru/Pt ratios are distinguished in detail. Finally, the Pt0.8Ru0.8/MCM-41 catalyst showed excellent catalytic activity (TOF: 823.9 h-1), glyceric acid selectivity (80.1%) and stability (recycling for 5th) under the optimized conditions (80 oC, 1 MPa O2 and 12 h). The insights and methodology reported here may pave the way to the rational design of bimetallic catalysts for efficient conversion of bio-derived substrates under mild conditions Figure 1. Plausible oxidation mechanism on the Pt0.8Ru0.8/MCM-41 catalyst.

關(guān)鍵詞

甘油氧化;理論計(jì)算

線上墻報(bào)僅限年會(huì)已繳費(fèi)參會(huì)代表觀看。

您還沒(méi)有登錄，請(qǐng)您先 點(diǎn)擊這里登錄