Metal-organic-frameworks (MOFs) possess the qualities of being a suitable catalyst with its high surface area, tunable functional groups and numerous uncoordinated active sites. However, low hydrothermal stability and poor resistance to acidic medium hinder its usage as catalysts in dehydration reactions to produce biofuels or fine chemicals. Typically, the Lewis acidic chromium sites of MIL-101 (Cr) enable catalysis of the xylose dehydration reaction up to 49% of furfural yield at 170 degrees C. Unfortunately, the durability of pristine MOF is still questionable, which can only be recovered for 4 times. This work reports a way to improve hydrothermal stability of MIL-101 (Cr) by functionalizing it with hydrophobic octadecyltrichlorosilane (OTS) without any significant negative impacts on its catalytic activity. The coated MOF, MIL-OTS-0.5, provides a yield of 56% with high durability of catalytic activity up to 8 reaction cycles. The confinement of the active sites within silane groups facilitates the MIL-OTS to retain their structure and properties over pristine MIL-101 (Cr). Moreover, addition of 35 ppt NaCl in the aqueous phase in presence of MIL-OTS-0.5 enhances the furfural yield up to 62.6%.