Understanding the Role of Boron on the Interface Modulation of thePd/TiO2 Catalyst for Direct Synthesis of H2O2
Understanding the Role of Boron on the Interface Modulation of thePd/TiO2 Catalyst for Direct Synthesis of H2O2
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DOI：
10.1021/acssuschemeng.1c07762
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发表时间：
2022-03-14
影响因子：
8.4
通讯作者：
Yuan, Shaojun
中科院分区：
文献类型：
--
作者：
Liu, Shijie;Deng, Yanbo;Yuan, Shaojun
合理调节金属-载体相互作用是提高负载催化剂催化性能的有效策略。在Pd和TiO2的界面处掺杂硼原子，增强了h2o2和o2直接合成h2o2的活性和选择性。在10℃、0.1 MPa的三相半连续反应体系中，硼掺杂后的h2o2的选择性和产率分别从63.4%和2.99 mol h2o2gpd -1h-1显著提高到80.1%和3.65 mol h2o2gpd -1h-1。采用HRTEM、XRD、XPS、sifrts等多种技术，深入研究了硼对Pd/ tio2结构的调制作用。掺杂硼原子对钯纳米粒子的粒径几乎没有影响，但增强了钯粒子与TiO2之间的强金属支撑相互作用（SMSI），从而改变了钯粒子的Pd2+/ pd0比和表面钯原子构型。适量的硼原子掺杂在pd - tio2界面上，增加了Pd2+的比例，为O2的非解离活化提供了更多的活性位点。此外，硼和钯之间的电子效应增加了对h2o2的吸附和活化，从而同时提高了h2o2的选择性和产率。本研究强调了调节金属-载体相互作用对h2o2直接合成的重要意义，也为通过界面掺杂提高负载型非均相催化剂的性能提供了一条有效而经济的途径。
Rational modulation of metal-support interactionis an effective strategy to enhance the catalytic performance of asupported catalyst. Here, both the activity and selectivity for thedirect H2O2synthesis from H2and O2are enhanced by the dopingof boron atoms at the interface of Pd and TiO2. With borondoping, the selectivity and productivity of H2O2are remarkedlyincreased from 63.4% and 2.99 mol H2O2gPd-1h-1to 80.1% and3.65 mol H2O2gPd-1h-1in a triphase semicontinuous reactionsystem at 10 degrees C and 0.1 MPa, respectively. The modulation effectof boron on the structure of Pd/TiO2was thoroughly studied byusing multiple techniques such as HRTEM, XRD, XPS, and in situDRIFTS. The doped boron atom almost has no effect on theparticle size of Pd nanoparticle, but enhances the strong metal-support interaction (SMSI) between the Pd particle and TiO2, which results in a change of the Pd2+/Pd0ratio and surface Pd atomsconfiguration. An appropriate amount of boron atoms doped at the Pd-TiO2interface increases the ratio of Pd2+species, providingmore active sites for the nondissociative activation of O2. Furthermore, the electronic effect between boron and Pd species increasesthe H2adsorption and activation, resulting in simultaneous increases in H2O2selectivity and productivity. This work highlights thesignificance of the modulation for metal-support interaction on direct H2O2synthesis, which also provides an effective andeconomic route by interface doping to improve the performance of supported heterogeneous catalysts.