Catalytic hydrogenation of isophthalonitrile (IPN) over supported monometallic and bimetallic catalysts

Abstract

The hydrogenation of Isophthalonitrile (IPN) to meta-xylylenediamine (m-XDA) is usually catalyzed by RANEY® or supported Ni based catalysts in the presence of a basic additive. The supported catalysts have better mechanical strength and are safer than RANEY® Ni catalysts. This work aimed to study the catalytic performance of g-Al 2 O 3 supported Ni and Ni-M (M ¼ Fe, Co, Cu) bimetallic catalysts in IPN hydrogenation. The H 2 -TPR results revealed that the introduction of a second metal enhanced the reducibility of Ni catalyst. The Ni-M bimetallic catalysts also had different metal dispersion, electronic properties and adsorption strength. Among Fe, Co and Cu, Fe showed the best promoting effect, which was attributed to the strong N-metal bonding and weak H-metal adsorption strength, which enhanced the catalytic activity and m-XDA selectivity. The catalytic performance also strongly depended on the Ni-Fe mass ratio. For the g-Al 2 O 3 supported Ni and Ni-M catalysts with a low Ni loading of 5 wt%, the rate constant k r increased from 0.024 mol 0.2 L À0.2 min À1 over 5Ni/Al 2 O 3 to 0.033 mol 0.2 L À0.2 min À1 over 5Ni-1.67Fe/Al 2 O 3 , meanwhile the m-XDA selectivity increased from 34.7% to 49.5%. Over the Ni-Fe bimetallic catalyst with high metal loading, 20Ni-5Fe/Al 2 O 3 , a very high m-XDA selectivity of 99.9% was obtained. Fig. 5 Effect of the Ni-Fe ratio on catalytic performance of Ni-Fe/ Al 2 O 3 catalysts (a) Ni + Fe ¼ 6.25 wt%, (b) Ni ¼ 5 wt%.This journal is

“BTX” from Guaiacol HDO under Atmospheric Pressure: Effect of Support and Carbon Deposition

“…Moreover, the reduction of Fe 2 O 3 to Fe 3 O 4 is in the region 300–400 °C, and the region 400–700 °C is assigned to reduction of Fe 3 O 4 to FeO and Fe. , For all the Ni/Fe/γ-Al 2 O 3 catalysts, the reduction of Ni/Fe oxides had two peaks at around 280–450 °C and in the range 450–700 °C, which were lower than those of the characteristic peaks of the monometallic Ni and Fe catalysts. The H 2 -TPR results indicated the formation of Ni–Fe bimetallic oxides (the result was consistent with the XRD pattern), which had a higher reducibility than the Ni and Fe monometallic oxides …”

“…The H 2 -TPR results indicated the formation of Ni−Fe bimetallic oxides (the result was consistent with the XRD pattern), which had a higher reducibility than the Ni and Fe monometallic oxides. 24 The H 2 -TPR results also indicated Fe/Ni/MCM-41 catalysts had a higher reducibility than other catalysts. For example, the reduction peak for Ni−Fe bimetallic oxides starts from 220 °C, while it starts from 300 °C for Fe/Ni/zsm-5.…”

“…It is well-known that the reduction peaks of Ni oxide were at 450 °C and in the range of 600−750 °C. 24 Moreover, the reduction of Fe 2 O 3 to Fe 3 O 4 is in the region 300−400 °C, and the region 400−700 °C is assigned to reduction of Fe 3 O 4 to FeO and Fe. 25,26 For all the Ni/Fe/γ-Al 2 O 3 catalysts, the reduction of Ni/Fe oxides had two peaks at around 280−450 °C and in the range 450−700 °C, which were lower than those of the characteristic peaks of the monometallic Ni and Fe catalysts.…”

Boosting Amination of 1‐Octanol to 1‐Octylamine via Metal‐Metal Oxide Interactions in NixFe1/Al2O3 Catalysts

“…Compared to the monometallic catalyst, the bimetallic Ni x Fe 1 /Al 2 O 3 catalyst had two main reduction peaks. The peak at ∼390 °C was attributed to the reduction of NiFe bimetallic oxides, while the peak at ∼525 °C was assigned to the reduction of less reducible Ni/Fe monometallic oxides [22] . However, the Ni and Fe oxides exhibited different reduction behaviors.…”

Selective Heterogeneous Catalytic Hydrogenation of Nitriles to Primary Amines

“…Nickel is a typically applied catalyst in the hydrogenation of nitriles in different forms, such as Raney-type one [10-14, 16-18, 24, 25], supported on silica [7,[26][27][28][29][30], alumina [31][32][33][34] or sepiolite [35], as well as NiAl alloy [36], Ni nanoparticles [37][38][39] or Ni 2 P [40].…”