A mini review on oxidative dehydrogenation of propane over boron nitride catalysts

Oxidative dehydrogenation of propane is an attractive route for the synthesis of propylene due to its favorable thermodynamic and kinetic characteristics, however, it is challenging to realize high selectivity towards propylene. Recently, it has been discovered that boron nitride (BN) is a promising catalyst that affords superior selectivity towards propylene in oxidative dehydrogenation of propane. Summarizing the progress and unravelling the reaction mechanism of BN in oxidative dehydrogenation of propane are of great significance for the rational design of efficient catalysts in the future. Herein, in this review, the underlying reaction mechanisms of oxidative dehydrogenation of propane over BN are extracted;the developed BN catalysts are classified into pristine BN, functionalized BN, supported BN and others, and the applications of each category of BN catalysts in oxidative dehydrogenation of propane are summarized;the challenges and opportunities on oxidative dehydrogenation of propane over BN are pointed out, aiming to inspire more studies and advance this research field.

Oxidative dehydrogenation of propane over Ni-Mo-Mg-O catalysts

In this work, a series of Ni-Mo-Mg-O catalysts with mesoporous structure prepared by sol-gel method were investigated for the oxidative dehydrogenation of propane （ODHP）. The techniques of temperature-programmed reduction with H2 （H2-TPR）, N2 adsorption-desolption, Fourier transform infrared spectroscopy （FT-IR）, X-ray diffraction （XRD） and X-ray photoelectron spectra （XPS） were employed for catalyst characterization. It is found that the activity of the catalysts for ODHP increases first and then decreases with the increase of Mo content. The catalyst with a Mo/Ni atomic ratio of 1/1 exhibits the best catalytic activity, which gives the propene selectivity of 81.4% at a propane conversion of 11.3% under 600 ~C and maintains the good catalytic performance for 22 h on stream. This is related not only to its high reducibility and dispersion as revealed by TPR and XRD, but also to the formation of more selective oxygen species on the MoOz-NiO interface as identified by XPS.

OXIDATIVE DEHYDROGENATION OF PROPANE OVER MCl_n/V-Mg-O CATALYSTS

Oxidative dehydrogenation of propane over V-Mg-O and MCl_n(M=Cu^+,Li^+, Ag^+,Cd^(2+))promoted V-Mg-O catalysts was studied.XRD result showed that the V-Mg-O catalysts were composed of MgO and Mg_3(VO_4)_2.The yield of propene was much higher over CuCl and LiCl promoted VMgO catalysts than that over VMgO catalysts at the same reaction temperature.The highest yield of propene reached 23.1% at 500℃ and 6000h^(-1) space velocity.

P-modified cobalt oxide: A novel and effective catalyst for oxidative dehydrogenation of propane

A series ofnanosized cobalt oxide catalysts modified with phosphorus have been synthesized by the solgel method and investigated in the oxidative dehydrogenation of propane to propene. With the addition of phosphorus, the crystallite size of the catalyst was largely decreased, while the P species in the catalyst were highly dispersed. Compared to pure cobalt oxide, the P-modified samples showed higher propane conversion and enhanced propene selectivity. Over the PCoO catalyst with a P/Co atomic ratio of 0.05, the maximal propene yields of 15.7% with a propane conversion of 28.3% were obtained at 520 ℃.

Supported ZnO catalysts for the conversion of alkanes:About the metamorphosis of a heterogeneous catalyst

ZnO could be a suitable catalyst for the oxidative conversion of CH4,C2H6 and C3H8.However,the main drawback is its thermal instability.Therefore,ZnO supported on ZrO 2,TiO2,γ-Al2O and SiO2 was investigated for the oxidative dehydrogenation of propane and ethane,and the oxidative coupling of methane.The stability of the supported ZnO is partially improved,but ZnO reacts with the support material,forming new compounds （Zn-zirconates,-titanates,-aluminates and-silicates）,which already occurs below reaction temperature.This might also be the case for many other heterogeneous catalysts.

Catalytic dehydrogenation of propane to propylene over highly active PtSnNa/γ-Al2O3 catalyst

PtSnNa/γ-Al2O3 catalyst is widely used in the dehydrogenation of light alkane. This paper reports a new fabrication method of the catalyst. In the work, γ-Al2O3, SnCl4 and NaCl were ball milled to upload Sn and Na＋ onto the support instead of the conventionally used immersion method. The subsequent baking procedures frimly fixed Sn onto the support, which could disperse Pt introduced by immersion. The effects of Sn and Na＋ additives on the catalytic performance of PtSnNa/y-Al2O3 catalyst were investigated. It was found that the appropriate molar ratio of Sn/Pt was 6：1 while the favorable weight percentage of Na＋ was 0.90%. Compared with the reaction catalyzed by the industrially employed PtSnNa/ γ-Al2O3 catalyst, the conversion of propane and the selectivity of propylene had been greatly improved, which were 26.97%; and 99.18% respectivelv after 12 h reaction.