Role of Boron in Enhancing the Catalytic Performance of Supported Platinum Catalysts for the Nonoxidative Dehydrogenation ofn-Butane

Abstract

Platinum-based supported catalysts for hydrocarbon conversion are among the most effective for selective dehydrogenation and isomerization processes. However, high process temperatures and the possibility of coke formation require catalyst modifications to mitigate such effects. One of the emerging approaches to prevent platinum catalyst deactivation is the use of boron additives that have been proposed to prevent coking. Despite such a valuable property of boron, the mechanisms for extending the catalyst lifetime and the decrease in coke formation based on this method are still poorly understood. The type and transformations of boron species on silica surface were investigated as a function of boron introduction, platinum addition, catalyst activation, and catalytic reactivity by a combination of X-ray photoelectron spectroscopy, electron microscopy, solid-state nuclear magnetic resonance spectroscopy, and density functional theory calculations to uncover the possible role of boron modification in improving the catalytic performance. Catalytic nonoxidative dehydrogenation of n-butane revealed that incorporation of boron improved the catalytic activity (∼3×) and stability of Pt/SiO2. The role of boron in enhancing catalytic performance was attributed to facilitating the migration of alkyl groups from platinum catalytic centers to tetrahedrally coordinated boron sites.

Ab Initio Multiscale Process Modeling of Ethane, Propane and Butane Dehydrogenation Reactions: A Review

“…The results showed that the presence of boron improves the catalyst stability for non-oxidative dehydrogenation of n-butane. Also, the rate of n-butane conversion over Pt/B/SiO 2 was found to be more than two times better as when using Pt/SiO 2 , throughout the duration of the reaction (25 h) [62].…”

“…Pt-based catalysts on various supports are among the most effective catalysts for selective dehydrogenation and isomerisation processes. However, high process temperatures and the possibility of coke formation require catalyst modifications to mitigate such effects [62]. Such catalysts were studied by Byron et al with Pt/B/SiO 2 [62], Silvestre-Albero et al with Pt-Zn/X-zeolite [63] and Casanave et al with Pt-In [64].…”

“…However, high process temperatures and the possibility of coke formation require catalyst modifications to mitigate such effects [62]. Such catalysts were studied by Byron et al with Pt/B/SiO 2 [62], Silvestre-Albero et al with Pt-Zn/X-zeolite [63] and Casanave et al with Pt-In [64]. One of the emerging approaches to prevent Pt catalyst deactivation is the use of boron additives that have been put forward as an alternative to prevent coking.…”

Heterogeneous alkane dehydrogenation catalysts investigated via a surface organometallic chemistry approach

“…Besides the combination of late and post-transition metals a recent study by Teplyakov et al utilizes the SOMC approach to combine Pt and B supported on SiO 2 for butane dehydrogenation. 122 The material was synthesized via sequential grafting of B(OiPr) 3 and [(MeCp)PtMe 3 ] onto partially dehydroxylated SiO 2 with an intermediate calcination step at 400 °C. A treatment under H 2 yielded 2.6 nm monometallic Pt particles supported on B doped SiO 2 as evidenced by HAADF-STEM and HR-TEM.…”

A Robust and Efficient Propane Dehydrogenation Catalyst from Unexpectedly Segregated Pt2Mn Nanoparticles

“…In order to find suitable materials, research efforts have concentrated on the use of post transition metal or main group element promoters like Zn [6][7][8][9][10][11][12][13] , B 14,15 , Ga [16][17][18][19][20] , In [21][22][23] and Sn 1,5,24 in combination with varying supports. All these promoters are known to drastically increase the PDH performance compared to monometallic Pt by increasing both selectivity and stability.…”