Effect of Pore Structures on 1,4-Butynediol Hydrogenation over Mesoporous Ni/Al₂O₃-SiO₂ Catalysts

Abstract

This work describes the 1,4-butynediol (BYD) hydrogenation to 1,4-butanediol (BDO) performance over supported Ni/Al2O3-SiO2 catalysts with different mesoporous structures (cross pore C-Ni/Al-SiO2, parallel pore P-Ni/Al-SiO2, and nonmesoporous structured N-Ni/Al-SiO2). To illustrate the pore structure effects on the catalyst texture, metal–support interaction, and surface acidity, the obtained catalysts were characterized using BET, inductively coupled plasma (ICP), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), H2 temperature-programed reduction (H2-TPR), and H2/NH3-temperature-programmed desorption (H2/NH3-TPD). Based on this, we proposed the structure–activity relationship between the pore structures and the hydrogenation performance. It was found that C-Ni/Al-SiO2 had short-range staggered and cross mesopores throughout the support, which can provide a larger surface area and pore volume for the fixation of highly dispersed active sites, thus enhancing the H2 activation ability. On the other hand, the cross channels have rich hole loops and surface defects for exposing assistant acid sites that are beneficial for the 1,4-butynediol (BYD) adsorption/activation, thus promising a superior hydrogenation ability. However, the narrow and long parallel pore structure of P-Ni/Al-SiO2 may limit the rapid diffusion of long-carbon-chain BYD in the pores, thus partially decreasing the accessibility of active sites and the catalytic activity. As for N-Ni/Al-SiO2, which has no mesoporous structure, its nickel particles are prone to aggregate seriously on the support surface, which weakens the interaction with the support and is not conducive to catalytic hydrogenation.

Investigation of Ni–Cu-acid multifunctional synergism in NiCu-phyllosilicate catalysts toward the 1,4-butynediol hydrogenation to 1,4-butanediol

“…The three catalysts all have a H 2 desorption peak (α-H peak) at about 80 °C, which is attributed to weak hydrogen adsorption at the interface of metals or the phyllosilicate support. 11,32 In addition, a particular high temperature (100–150 °C) desorption peak (β-H peak) appeared in some special catalysts, which may be attributed to the strong hydrogen adsorption originating from the highly active differentiated Ni mentioned above. 43,44 It should be pointed out that the β-H does not only appear to be characteristic of the NiCu alloy for adsorbed H, but also represents another substrate (H 2 ) activation opportunity for the enhanced CC/CC full-hydrogenation selectivity of BYD/BED to BDO.…”

“…), 9 RANEY® Ni 10 and supported Ni-based catalysts. 11 Among these, the noble metals cannot be used on a large scale in industry due to their high cost and limited reserve, while RANEY® Ni has problems with insecurity, low selectivity and easy deactivation. 12 The supported Ni-based catalysts also have some drawbacks, such as low metal loading, strict requirements for activation, low chemoselectivity, and metal loss during liquid phase hydrogenation.…”

Highly Efficient Monolithic Catalyst with Excellent Adhesion of SiO2 Coating for Catalytic Hydrogenation in the Rotating Packed Bed Reactor

“…The XRD patterns of the nickel foam, SiO 2 /Nickel foam, and Pd/SiO 2 /Nickel foam monolithic catalysts are shown in Figure . The peak at 2θ = 20–30° was known to be the amorphous SiO 2 with tetrahedral short-range order, indicating the successful loading of SiO 2 onto the nickel foam surface . The Pd(111) (JCPDS card no.…”

Porous Mn2O3/pSiO2 Nanocomposites on Bio-scaffolds for Tetracycline Degradation

“…On the other hand, bulk Mn 2 O 3 with a large particle size and low specific surface area generally has limited exposed active sites and poor catalytic activity . Consequently, Mn 2 O 3 was loaded on supports such as carbon, g -C 3 N 4 , and graphene for better catalytic performance. − Porous silica is another commonly used material that can serve as good supports to disperse metal oxide nanoparticles (NPs) due to its high porosity, good thermal stability, and structural flexibility. , However, how to disperse Mn 2 O 3 NPs into a porous SiO 2 matrix with the desired structure for better electron transfer is still a great challenge.…”

“…26−28 Porous silica is another commonly used material that can serve as good supports to disperse metal oxide nanoparticles (NPs) due to its high porosity, good thermal stability, and structural flexibility. 29,30 However, how to disperse Mn 2 O 3 NPs into a porous SiO 2 matrix with the desired structure for better electron transfer is still a great challenge.…”