Synthesis of Porous Particles of SOFC Anode and Cathode Materials by Citric Acid-Addition Ultrasonic Spray Pyrolysis (CA-USP)

Figures & data

FIG. 1. Concept of citric acid-addition ultrasonic spray pyrolysis (CA-USP).

FIG. 2. Temperature profiles in the reactor at T_f1 = 673 K, T_f2 = 873, 1073, and 1273 K, and Q = 5 L min⁻¹.

TABLE 1 Average crystallite sizes D_cry obtained from XRD patterns for NiO-GDC, LSC, and LCM particles shown in Figure 4

	NiO-GDC
Cc [mol/L]	NiO Dcry [nm]	GDC Dcry [nm]	LSC Dcry [nm]	LCM Dcry [nm]
0	19	20	39	43
0.2	11	17	39	34

FIG. 3. XRD patterns of (a) NiO-GDC, (b) LSC, and (c) LCM powders synthesized at C_total = C_c = 0.2 mol L⁻¹, T_f1 = 673 K, T_f2 = 1273 K, and t_r = 16 s with JCPDS 78-0643 of NiO and JCPDS 78-0161 of GDC, JCPDS 36-1392 of LSC, and JCPDS 44-1040 of LCM (white and black bars).

TABLE 2 Geometric mean diameters D_pg and geometric standard deviations σ_g obtained from SEM images of NiO-GDC, LSC, and LCM particles shown in Figure 5

	NiO-GDC		LSC		LCM
Cc [mol/L]	Dpg [nm]	σg [−]	Dpg [nm]	σg [−]	Dpg [nm]	σg [−]
0	475	1.21	549	1.35	576	1.23
0.2	523	1.30	616	1.33	663	1.28

FIG. 4. SEM images of (a) NiO-GDC, (b) LSC, and (c) LCM powders synthesized at C_c = 0 mol L⁻¹ and (d) NiO-GDC, (e) LSC, and (f) LCM powders synthesized at C_c = 0.2 mol L⁻¹. (C_total = 0.2 mol L⁻¹, T_f1 = 673 K, T_f2 = 1273 K, and t_r = 16 s.)

FIG. 5. TEM images of NiO-GDC, LSC, and LCM powders synthesized at C_c = 0 mol L⁻¹ and C_c = 0.2 mol L⁻¹. (C_total = 0.2 mol L⁻¹, T_f1 = 673 K, T_f2 = 1273K, and t_r = 16 s.)

TABLE 3 Specific surface areas S_w obtained from N₂ adsorption isotherms of NiO-GDC, LSC, and LCM particles

Cc [mol/L]	NiO-GDC Sw [m^2/g]	LSC Sw [m^2/g]	LCM Sw [m^2/g]
0	12.0	39.0	3.9
0.2	14.1	48.0	22.7

FIG. 6. High magnification SEM images of NiO-GDC, LSC, and LCM powders synthesized at C_c = 0 mol L⁻¹ and C_c = 0.2 mol L⁻¹. (C_total = 0.2 mol L⁻¹, T_f1 = 673 K, T_f2 = 1273 K and t_r = 16 s.)

FIG. 7. EDX images of NiO-GDC particles synthesized at C_c = 0 mol L⁻¹ and C_c = 0.2 mol L⁻¹. (C_total = 0.2 mol L⁻¹, T_f1 = 673 K, T_f2 = 1273 K, and t_r = 16 s.)

FIG. 8. Number size distributions of (a) NiO-GDC and (b) LCM particles measured by DLS before (solid lines) and after (dotted lines) a 2-h ball mill grinding. Particles were synthesized at C_total = C_c = 0.2 mol L⁻¹, T_f1 = 673 K, T_f2 = 1273 K, and t_r = 16 s.

FIG. 9. XRD patterns of GDC particles synthesized at T_f1 = 673 K, T_f2 = 473, 673, 873, and 1073 K (C_total = C_c = 0.2 mol L⁻¹ and t_r = 16 s) with JCPDS 78-0161 of GDC (black bars).

FIG. 10. SEM images of GDC particles synthesized at T_f1 = 673 K, T_f2 = (a) 473, (b) 673, (c) 873, and (d) 1073 K. C_total = C_c = 0.2 mol L⁻¹, and t_r = 16 s.