Electronic Supplementary Information
Experimental details
Catalyst preparation
Different Ni-based catalysts (10 wt% nominal loading) were prepared by incipient impregnation following chemical reduction with KBH4 aqueous solution, using NaMOR zeolite (surface area=105 m2/g), NaZSM-5 zeolite (surface area=331 m2/g), NaA zeolite (surface area=18 m2/g), NaX zeolite (surface area=925 m2/g), SiO2 (surface area=709 m2/g), and γ-Al2O3 (surface area=162 m2/g) as supports, respectively. All the supports were commercially available (NaMOR, Dalian Liding Natural Products Co., Ltd, China; NaZSM-5, Nankai UniversityCatalystCo., Ltd, China; NaA and NaX, Dalian Samat Chemicals Co., Ltd, China; SiO2, W. R. Grace & Co., USA; γ-Al2O3, Shandong Aluminum Industry Co., Ltd, China). The surface area of NaMOR is a little low that might be due to its poor crystallinity. With respect to NaA, the low surface area might be attributed to the hampered N2 adsorption in the small pore structure if containing bulky alkali ions. All of the support materials were dried at 120 oC for 12h prior to use.
NaX zeolites containing different amount of Na+ ions were prepared as follows: they were exchanged with 1.0 M NaNO3 solution at 80 oC for 3 h, followed by filtration, dried at 120 oC for 12 h, and calcined at 500 oC for 5 h. The samples of exchanging for two times and four times were named NaX1 and NaX2, respectively. The NaX0 zeolite was obtained through ion-exchanged for three times with 1 M NH4NO3 solution at 80 oC for 3 h.
In a typical preparation supported Ni catalyst was prepared as follows: NaX was impregnated for 24 h with equivalent volume of an aqueous NiCl2 solution. After being dried it was reduced by adding KBH4 (1.0 M) solution dropwise under vigorous stirring in an ice-water bath. The resulting black precipitate sample was then separated and thoroughly washed to remove the residual ions. The obtained catalyst is designated as Ni/NaX. For comparison, unsupported Ni powder was prepared according with the above procedure without support, and Ni powder-NaX catalyst was prepared by mechanical mixing Ni with NaX.
Analysis method
The samples were analyzed by Agilent 4890 gas chromatography using capillary column HP-5 (30 m × 0.53 mm × 1.5 μm) equipped with a flame ionization detector (FID). The operating parameters were as follows: column temperature programming：Holding for 1 min at 130 oC, then increasing to 220 oC at a rate of 40 oC per minute; inject temperature: 250 oC; detector temperature: 280 oC. Agilent Chemstation software was adopted to analyze the data. Benzyl alcohol was added as internal standard for analysis. The relative deviations of EG, 1,2-PG and glycerol were 0.84%, 0.08% and 1.97%, respectively. And their relative errors were 1.97%, -0.07%, and 0.44%, respectively. Products were also identified by GC-MS (Agilent 6890N GC/5873 MS, column: SE-54) and MS (Omnistar).
The conversion of glycerol, selectivity of EG and 1,2-PG were defined as the following equations:
Table S1 The Si/Al ratio of NaX zeolitesa
Sample / NaX2 / NaX1 / NaX / NaX0Si/Al ratio / 1.18 / 1.19 / 1.18 / 1.20
a determined by the elementary analysis.
Fig. S1. GC-MS of products in the hydrogenolysis of glycerol over Ni/NaX catalyst.
1) Mass spectrometry of acetol.
2) Mass spectrometry of EG.
3) Mass spectrometry of 1,2-PG.