# Nickel-Based Structured Catalysts for Indirect Internal Reforming of Methane
## Materials and Methods
Before analysis, the sample was degassed at 350 \({}^{\circ}\)C under vacuum for 4 h.  
Insights into morphology and chemical composition of NiCrAl foam were obtained through the combination of the field emission scanning electron microscope (FE-SEM) SUPRATM [35], Carl Zeiss STM, Oberkochem, and the energy-dispersive X-ray spectroscopy (EDX). Furthermore, a FE Helios NanoLab 600 DualBeam integrating both a FE-SEM column and a focused ion beam (FIB) column allowed us to perform in plane inspection and cross-sectional analysis in order to reveal, respectively, the morphology and the thickness of the catalyst coating on the NiCrAl support. The FIB system was equipped with a Ga\({}^{+}\) ion source operated at 30 kV acceleration and was used with beam currents in the 9.2-21 nA and 0.92-2.8 nA ranges for the milling and polishing steps, respectively. FIB cross-sectional analysis combined with EDX spectroscopy allowed us to highlight the chemical composition of the oxidized surface and of the inner NiCrAl alloy foam. Raman spectroscopy analysis on the foam was carried out using a Jobin Yvon micro-Raman LabRam 800 system. Measurements were performed at room temperature in the backscattering geometry, using a green laser (excitation wavelength, 532 nm) with a power of 20 mW. Spectra were recorded in the range 100-800 cm\({}^{-1}\), with an acquisition time of 10 s with three accumulations. The reduction behavior of the metal foam, catalyst powder, and final structured catalyst was investigated. Temperature programmed reduction experiments were performed using a TPDRO 1100 instrument by Thermo Fisher Scientific. The samples were pretreated flowing 20 cm\({}^{3}\) min\({}^{-1}\) of a 5% O\({}_{2}\)/He mixture at 500 \({}^{\circ}\)C for 30 min. The samples were cooled to room temperature and then H\({}_{2}\)-TPR experiments were carried out, flowing 5% H\({}_{2}\)/Ar mixture (30 cm\({}^{3}\) min\({}^{-1}\)) with a heating rate of 10 \({}^{\circ}\)C min\({}^{-1}\) up to 800 \({}^{\circ}\)C, keeping the system in isotherm condition for 1 h. The samples were finally cooled to room temperature in the reduction mixture flow with a rate of 25 \({}^{\circ}\)C min\({}^{-1}\) to prevent the sample oxidation. The catalytic measurements were performed in a laboratory micropplant, equipped with a fixed-bed quartz reactor (internal diameter 10 mm; external diameter 14 mm) connected with a mass flow controllers instrument for incoming gases. The composition of reaction stream was online analyzed using a gas chromatograph Agilent 7820 equipped with two packed columns (Hayesep Q for CO\({}_{2}\) separation and X13 Molecular Sieve for the CO, CH\({}_{4}\), H\({}_{2}\), Ar separation) and a thermal conductivity detector (TCD). The catalyst portions were reduced in situ at 800 \({}^{\circ}\)C for 1 h, flowing 5% H\({}_{2}\)/Ar gas mixture (50 cm\({}^{3}\) min\({}^{-1}\)) with a heating rate of 10 \({}^{\circ}\)C min\({}^{-1}\). After catalyst activation, the reactant mixture (100 cm\({}^{3}\) min\({}^{-1}\)) CH\({}_{4}\):CO\({}_{2}\):N\({}_{2}\):He = 20:20:10:50 (vol %) was fed in the reactor. The overall catalytic test was repeated for four cycles to investigate the catalyst stability and, after each test, the reactor was cooled under N\({}_{2}\) flow (10 cm\({}^{3}\) min\({}^{-1}\)) to prevent the oxidation of the active phase. The reduction treatment was carried out over 1 h before the first testing cycle and over 30 min for the next cycles. These conditions mimicking a daily start-up and shut-down operation (DSS) are schematized in Figure S1. CH\({}_{4}\) and CO\({}_{2}\) percent conversions (X\({}_{i}\) %) were calculated according to Equation (5) using nitrogen as internal standard, in which \(C_{i}^{0}\) and \(C_{N2}^{0}\) are the inlet concentrations (%) of the reactant (i = CH\({}_{4}\) or CO\({}_{2}\)) and N\({}_{2}\), respectively, and \(C_{i}\) and \(C_{N2}\) are the outlet concentrations. Thermodynamic equilibrium conversions were calculated using GASEQ software.