Data set relating to Catalytic response and stability of Ni/Alumina prepared from layered double hydroxides for the hydrogenation of 5-hydroxymethyl furfural in water

Sample name in paper	File reference
NiAl-1				CA-01
NiAl-2				CA-02
NiAl-3				CA-03
NiAl-4				CA-04



Catalyst Preparation 
Four catalyst precursors Ni(1-x)Alx(OH)2(CO3)x/2.mH2O, with 0.24 = x = 0.47 and 0.3 = m = 0.7, were prepared by co-precipitation with urea, based on Costantino et al. method [27]. A known mass of powder urea (Sigma) was placed in a reaction flask (250 mL) with distilled water (50 mL). A mixture of 1.5 M aqueous solutions of AlCl3·6H2O (Fluka, = 99.0 wt% purity) and NiCl2·6H2O (Aldrich, 99.9 wt% purity) were added. The volumes of the solutions and the mass of urea were appropriately chosen to have the Al ratios (x) = nAl/(nNi + nAl) in the range 0.24-0.47 and nurea/(nNi + nAl) = 3.3. The flasks were placed in a Radley Carousel 6 Plus station, stirred at 750 rpm and heated to 368 K at 1K min-1 under reflux. After aging for 65 h, the solutions were cooled to ambient temperature and filtered. The precipitated materials were left in suspension with NH4HCO3 for 5 h (to remove any residual Cl), then filtered, washed and dried at 2 K min-1 to 353 K for 3 h. The solids were then ground and dried at 2 K min-1 to 393 K for 5 h; the precursors are denominated NiAl-XP, with X = 1, 2, 3 and 4. The samples were placed in a furnace (0.35 g of powder per crucible) and successively calcined (under air, 75 mL min-1, NiAl-XC) and reduced (under pure H2, 100 mL min-1) at 5 K min-1 to 773 K for 5 h; the catalysts were then passivated (<1% v/v O2/N2, 100 mL min-1) at room temperature for 3 h (NiAl-XR).

Catalysts Characterization
Total surface area (SA), pore volume (PV) and pore size distribution of the precursors and catalysts were determined by volumetric N2 adsorption at 77 K, with a Tristar II micromeritics. Thermal gravimetric analysis (TGA) were measured with a Q500 TA Instruments; ca. 10 mg of samples heated to 1023 K at 5 K min-1 under 50 mL of air or Ar and changes in mass were recorded. Temperature programmed reduction (TPR) was measured using the commercial CHEM-BET 3000 (Quantachrome) unit; 50 mg of samples were loaded into a Quartz cell, heated in 30 mL min-1 5% v/v H2/N2 at 5 K min 1 to 773-1073 K and changes in H2 consumption were monitored by TCD. Carbon and hydrogen contents of the materials were determined by microanalytical procedures using a Thermo EA1112 Flash CHNS Analyser. Al and Ni contents of the catalysts and solutions were measured by inductively coupled plasma-optical emission spectrometry (ICP-OES) after digesting 25 mg of the material in 10 mL of HCl (37%) for 4h and diluting it with water (1/10 v/v).
The precursors and catalysts were sputter coated with gold and images were recorded with a Hitachi S-4800 Field-Emission Scanning Electron Microscope; Ni, Al and Cl content were obtained by SEM-EDX. A small amount of sample was deposited on the carbon film of a copper grid and Ni particle size distribution was obtained using a JEOL 2100 Transmission Electron Microscopy (TEM).
The precursors were ground and combined with oven dried KBr and pressed into a disc. The spectra of the samples were recorded by accumulating 64 scans at 4 cm-1 resolution between 400 and 4000 cm-1 using a Fourier Transform Infrared (FT-IR) Bruker Tensor 27.
Powder X-ray diffractograms (XRD) data were collected in reflection geometry on a Panalytical X’Pert Pro diffractometer with Co Ka1 radiation (? = 1.7890 Å). Samples were scanned at 0.023º s-1 over the range 10º = 2? = 80º for phase identification using the reference standards, i.e. Ni (Card No. 73-1519), NiO (70-0989). Samples were mixed with LaB6 as an internal standard and the powders were scanned over the range 10º = 2? = 120º for whole pattern fitting; the lattice parameters of the materials were obtained performing Pawley refinement using Topas academic software, with the cell parameter of LaB6 (space group Pm3m; a = 4.15700 Å) fixed. The mean particle sizes (dNi) were determined using the Double-Voigt approach based on the method of Balzar et al. [60,61] and assuming a mono-disperse system of spheres. Specific Ni surface areas were obtained with, 
S_Ni=6/(??×d?_Ni )                                                (9)
With ? the Ni specific mass.
The isoelectric points (IEP) were determined by measuring the change in zeta potential as a function of pH. In each case, ca. 10 mg of catalyst was dispersed in 10mL of distilled water; the zeta potentials were obtained by measuring the electrophoretic mobility of the particle using a Malvern Zetasizer Nano ZSP Instrument. The pH was controlled with a MPT-2 titrator (adding HCl or NaOH, 0.025 M) and 10 measurements were conducted between pH 6 and 12. 

Catalytic testing
Reactions were carried out in a batch stirred stainless steel Parr 5000 reactor. In a typical experiment 0.01-0.14 g of catalyst and 45 mL aqueous solution of reactant (C = 0.02-0.04 M) were charged in a glass liner. The reactor was then closed, flushed under N2, stirred (600 rpm) and heated to reaction temperature (353-413 K). After stabilisation of the temperature (ca. 1 h), H2 was added and the reactor was kept under constant pressure (5-60 bars). The product composition and identification was determined using an Agilent Technologies 7890A gas chromatograph equipped with FID and an 6890N GC equiped with 5973 MSD agilent, respectively. A DB-WAXetr 60 m ? 0.25 mm i.d., 0.25 µm film thickness capillary column (Agilent J&W) was employed in both. Repeated reactions with different samples from the same batch of catalyst delivered a product composition that was reproducible to within ± 5%. A blank test conducted without catalyst did not result in any detectable conversion. 5-Hydroxymethyl furfural (Sigma, = 99 wt% purity) was used as received without further purification. furan-2,5-diyldimethanol (Manchester organics) and tetrahydrofuran-2,5-diyldimethanol (Ambinter) were used for identification and calibration of products.
5-hydroxymethyl furfural (HMF) conversion (X) at time t was calculated as
X=  (C_(HMF,in)-C_HMF)/C_(HMF,in)                                               (10)
CHMF,in and CHMF are the initial concentrations initial and at time t of HMF in solution, respectively. The selectivity (S) and yield (Y) with respect to furan-2,5-diyldimethanol (FDM), as an example, are given by,
S_FDM=  C_FDM/C_(HMF,in-C_HMF )        &     Y_FDM= S_FDM×X           (11)
Identification of tetrahydrofuran-2,5-diyldimethanol and 3-hydroxymethyl cyclopentanone were verified by 1H and 13C NMR using a Bruker Avance III HD NMR spectrometers operating at 400 MHz proton frequency. Water was removed from the solutions with a rotary evaporator and the compounds left were diluted in DMSO; chemicals shifts are reported relatively to residual solvent.