Preparation of Nanoscale Ni–Cu Supported Over Hydrochar by Hydrothermal Method and Effect of Ni/Cu Ratio on Catalytic Performances in Dry Reforming of Methane

In this study, Ni–Cu alloy nanoparticle catalysts for dry reforming of methane (DRM) were synthesized by one-step hydrothermal method. The results demonstrated that the addition of Cu into Ni/BC could form Ni–Cu alloy and strengthened the electron transfer, which was beneficial to smaller Ni particle size formation and higher dispersion of Ni particles. When Ni/Cu ratio was increased from 0 to 7:1 (Ni7Cu 1 /BC), Ni particle size was decreased from 8.56 to 6.32 nm. CH 4 and CO 2 conversion rate over Ni/BC were 40.21% and 75.90%, which were increased to 89.41% and 97.64% over Ni7Cu 1 /BC. Especially, Cu addition would inhibit the reverse water gas shift reaction, and H 2 /CO was obviously increased from 0.63 (Ni/BC) to 0.96 (over Ni7Cu 1 /BC). However, the excess Cu addition suppressed the catalytic activity for DRM. TG and TEM revealed that there was no obvious graphitic carbon on the used Ni7Cu 1 /BC, and CH 4 /CO 2 conversion rate was well kept after 24 h reaction. Graphical Abstract