Surface And Interface Structure Control Of Pt-Based Nanomaterials For Catalytic Applications

Rational design and controllable synthesis of stable and efficient catalysts are crucial for addressing the energy shortage.Pt-based nanomaterials are widely used in the field of energy conversion due to their excellent catalytic properties.A large number of studies have shown that there is a close relationship between the surface and interface structure of catalysts and catalytic performance.Therefore,in-depth study of the relationship between the surface interface structure and catalytic performance of Pt-based nanomaterials is the premise and basis for the development of efficient catalysts.In this paper,a simple synthesis method was used to finely control the surface and interface structure of Pt-based nanomaterials,and the effect of surface and interface structure control of Pt-based nanomaterials on the catalytic performance of methanol oxidation and light alkane dehydrogenation was systematically studied.The specific research contents are as follows:（1）Bi-modified Pt nanoparticle catalysts was developed,in which the alloying of partly Bi with Pt can effectively tune the electronic structure of Pt,making it appear electron-rich,thereby regulating the adsorption of Pt active sites to substrates and intermediates strength.In addition,the surface modification of a large amount of amorphous Bi2O3 can promote the generation of adsorbed OH radicals（OHads）and the oxidative elimination of adsorbed CO intermediates on the Pt active sites,thereby enhancing the catalytic activity and stability of Pt-based nanocatalysts in methanol oxidation reaction.The Pt0.7Bi0.3 nanoparticle catalyst has the best performance,and its current density is 6.3 times higher than that of pure Pt nanoparticle catalyst.After the 10000 s stability test,the current density of the Pt0.7Bi0.3 nanoparticle catalyst could be maintained at 36%of the initial activity,which is more stable than the pure Pt nanoparticle catalyst.（2）The construction of alkaline earth metal Mg-doped Pt-Ga/S-10 catalyst can effectively inhibit the dehydroisomerization,carbon deposition and excessive C-C cracking of n-butane,and can effectively inhibit the dehydrogenation of n-butane to 1,3Significantly improved 1,3-butadiene selectivity in n-butane dehydrogenation.In addition,Mg doping also helps to improve the dispersion of Pt active sites on the support surface,which increases the reactivity by exposing more Pt active sites in the case of neutralization of acidic active sites.At 625℃,0.1Pt·6Mg·2Ga/S-10 catalyst has the best performance,its n-butane conversion rate reaches 82.14%,and the 1,3-butadiene selectivity and space-time yield are 35.8%and 1.98 g·gcat.^-1·h^-1,respectively,and showed good stability in 100 dehydrogenation-regeneration cycle tests.