Xylose is a potential feedstock for hydrogen production. However, the slow C-C bond-scission, which reduces the hydrogen extraction efficiency, is one of the concerns for hydrogen production from Xylose. Using first principles-based density functional theory (DFT) calculations, we investigated the reaction mechanism for converting Xylose to ethylene glycol and glycerol precursors on MgO-supported small Ni cluster catalysts. We calculated the reaction energy and reaction barrier to determine the most favorable reaction pathway and rate-determining step (RDS) for the process, leading to an understanding of a descriptor representing the reactivity. Next, by substituting a single Ni atom from Ni trimer (Ni₃/MgO) with a transition metal M (M = 3d, 4d, 5d transition elements), we designed various supported Ni-based bimetallic catalysts (Ni₂M/MgO) and tested their catalytic activities. We found promising candidates (e.g., Ni₂Rh/MgO and Ni₂Ta/MgO) for enhanced C-C bond cleavage of xylose and correlated their descriptor with catalytic activity. The electronic structure analysis revealed that the d-band center of Ni₂Rh/MgO and Ni₂Ta/MgO is up-shifted compared to pure Ni trimer, contributing to their stronger adsorption.