Initially, p-phenylbenzyl alcohol 1a was chosen as the benchmark substrate for its electroreductive transformation into the corresponding alkane 2a using graphite (Cgr) electrodes in an undivided cell with NaBH4 as additive. Molecular sieves (MS) were added to the reaction to avoid hydrolysis of the borohydride (see Section 4.1 in the ESI), while the risk of overpressure from the anodic formation of H2 was circumvented by ventilation of the reaction vessel with a continuous flow of N2 through the headspace of the reaction. Under these conditions, the product alkane 2a formed in 60% yield (Table , entry 1) after three hours, using one equivalent of NaBH4 with respect to substrate 1a. The beneficial effect of the borohydride reagent on the yield of the desired product was confirmed by a control reaction that resulted in a 36% yield of 2a in its absence (Table , entry 2). The selectivity and yield for 2a increased upon the addition of borohydride with an optimum at 0.3 equivalents (Table , entries 3-4), while increased borohydride loading resulted in a slower consumption of 1a (Table , entry 5 and Section 4.2 in the ESI). A switch to Bu4NBH4 resulted in near quantitative yields of 2a even after 2 h (Table , entry 6). Quantitative yields were also obtained using a lead cathode (Table , entry 7), whereas the use of other electrode materials as well as other solvents resulted in lower yields (see Sections 4.4 and 4.5 in the ESI). Excellent reproducibility was observed using either new graphite electrodes or electrodes cleaned with acid and subsequent sonication prior to reuse (see Section 1 and 3 in the ESI). Both lower and higher concentrations compared to the initial 0.1 M of 1a resulted in lower yields of 2a after 2 h (Table , entries 6 vs. 8-9), likely the result of by-product formation in the former case and incomplete conversion in the latter due to different amounts of charge/mol substrate transferred. Removal of the gas outlet, i.e. stopping the dynamic flow of N2 through the reaction headspace, resulted in lower yields of 2a, lower conversion of 1a to products, and a less reproducible reaction (Table , entry 10). As expected, 2a was not formed in the absence of current. With the optimized conditions at hand, a variety of alcohols were evaluated for the electrochemical hydrodeoxygenation (Figure ). Selected primary, secondary, and tertiary benzylic alcohols were converted into the corresponding alkanes in high yields (2a-2g). Electron-donating groups such as alkyl chains and ethers were tolerated under the reaction conditions and resulted in products 2h-2l in good yields. In contrast, the acetal-protected diphenol 2m formed in mere 9% yield, whereas alkane 2o with a free phenol failed to form (see Section 13 in the ESI). Interestingly, while aryl and methyl ethers (2k-2l) were stable under the applied conditions, benzylic ethers resulted in selective C-O bond cleavage at the benzylic position to furnish products 2b, 2d/2ae and 2af in good yields. The hydrodeoxygenated thiophene and furan 2p and 2q formed in moderate to good yields, while substrates with basic heterocycles furnished only trace amounts of the expected products under the present condition (see ESI, Section 13). In addition, propargylic alcohols were converted into the corresponding alkene 2ag and alkane 2ah in 10% and 53% yield, respectively. Benzylic substrates with electron-withdrawing substituents, such as nitriles and esters, were well tolerated under the reaction conditions, and pcyanotoluene 2t formed in good yield, as was its secondary counterpart 2u. In contrast, sensitive benzylic cyanohydrin underwent side-reactions, and 2v was observed in mere trace amounts when subjected to standard conditions. The ester-substituted 2w formed in high yield from the corresponding alcohol, while the related alkane products 2x, 2ab and 2ac formed in moderate yields.