*2.3. Catalysts Characterization*

Specific surface areas and pore size distributions were evaluated by N<sup>2</sup> adsorption/desorption isotherms at −196 ◦C using a Tristal II Plus Micromeritics. (Micromeritics, Milan, Italy); The surface area was calculated using the Brunauer–Emmett–Teller (BET) Equation [27] method while pore size distribution was determined by the BJH (Barrett, Joyner, and Halenda) method [28], applied to the N<sup>2</sup> desorption branch of the isotherm.

The Ni and La contents were determined by atomic absorption spectroscopy (AAS) after microwave disaggregation of the samples (100 mg), using a Perkin-Elmer Analyst (Perkin-Elmer, Waltham, MA, USA); 100 spectrometer.

The morphology of the catalysts was studied by scanning electron microscopy (SEM) with a table-top Hitachi instrument, model TM-1000 (Hitachi, Ramsey, NJ, USA), after depositing the ground powder sample on a double-sided lacey carbon ribbon.

X-ray diffractograms were obtained on a Seifert XRD 3000P diffractometer; using nickel-filtered Cu Kα radiation operating at 40 kV and 40 mA, using a 0.02◦ step size and 2 s counting time per step. Analysis of the diffraction peaks was conducted with the software ANALYZE Rayflex Version 2.293.

Temperature programmed reduction (TPR) measurements were carried out using lab-made equipment: samples (100 mg) were heated with a temperature rate of 10 ◦C/min from 25 ◦C to 900 ◦C in a 5% H2/He flow (40 mL/min). The effluent gases were analyzed by a Thermal Conductivity Detector (GOW-MAC InstrumentCo., Shannon, Irland)

## *2.4. Catalytic Tests*

Catalysts were tested for ESR at 500 ◦C and atmospheric pressure, charging the feed with molar composition of water:ethanol:He = 18.4:3.1:78.5 and W/F = 0.12 gcat.h/mol ethanol, in a stainless steel, fixed bed tubular reactor placed in an equipment Microactivity Reference model MAXXXM3-(PID Eng and Tech, Madrid, Spain). Prior to the reaction, fresh catalyst samples were activated under flow of 10% O<sup>2</sup> in He at 650 ◦C for 1 h. Catalytic stability tests were conducted at 500 ◦C for 5 h. After the first run, the catalyst was cooled down and flushed under inert flow, and then reactivated using the same procedure of the initial activation, heating up to 650 ◦C at 10 ◦C/min and keeping this temperature for 1 h, under a flow of 10% O<sup>2</sup> in He. After cooling down to 500 ◦C in inert flow, a second run was conducted with the regenerated samples under the same condition of the first run. Tests for each sample were reproducible within experimental error. Reactants and products were analyzed online by GC on a Varian Star 3400 CX instrument (Varian, Cridersville, OH, USA); equipped with two columns, molecular sieve and Porapak Q and the detector of thermal conductivity. After the analysis, conversion of ethanol and hydrogen yield were calculated as follows:

Conversion of ethanol:

$$\text{conversion } (\%) = \left[ \frac{n\_{\text{in}}(EtOH) - n\_{\text{out}}(EtOH)}{n\_{\text{in}}(EtOH)} \right] \times 100\tag{1}$$

H<sup>2</sup> yield:

(green cross); NiLaCe P (blue rhombs); NiLaCe M (violet circle).

1).

particles.

$$yield\,\,\left(^{\circ}\right) = \,\frac{fH\,\,2\,\,out}{6 \times fEt\,\text{OH}\,\text{in}} \times 100\,\tag{2}$$

**ameter b (nm) Vpore c (cm3/g) NiO Mean Particle** 

**Size d (nm)**

with *n* number of moles; *f*, flux in mL/min.
