Evidence-screened literature comparison · 19 October 2026
NiMo vs Ni–VOx for lignin-phenolic HDO
What the published evidence can—and cannot—say about activity when the catalyst is hydrogen-reduced and non-sulfided. The requested threshold was at least seven papers per family; this review reports the verified shortfall rather than filling it with unrelated systems.
Bottom line: NiMo has several direct phenol/guaiacol HDO precedents, with reported high conversion and hydrocarbon/phenolic product yields depending strongly on support, reduction, and target pathway. For Ni–VOx, the search found one direct m-cresol study suggesting improved selective deoxygenation at a Ni–VOx interface. That is a promising hypothesis, not yet a replicated basis to rank NiVOx against NiMo. Seven qualifying papers were not verified for either catalyst family.
4direct NiMo / reduced-state papers screened; 3 with specific performance details available
1direct Ni–VOx phenolic-HDO paper located
0valid seven-paper-per-family comparisons in this evidence set
What “activity” means here
Conversion alone is not a fair activity ranking. The papers use different phenolics, supports, temperatures, hydrogen pressures, solvents/reactors, and product targets. A catalyst can consume the substrate but stop at phenol/cyclohexanol, or remove oxygen to aromatic/cycloalkane products; selectivity and yield therefore matter alongside conversion. No comparable rate/TOF dataset was established across NiMo and Ni–VOx.
Scope: direct HDO of lignin-derived phenolic model compounds; catalysts used in reduced/non-sulfided state. Sulfided-only results are excluded. Nitride/carbide catalysts and catalysts whose required H2-reduction state was not verified are kept out of the strict evidence count.
NiMo: direct reduced-state evidence
Kordouli et al. (2018) — phenol, Mo promotion and support
Direct; partially reduced
Hydrodeoxygenation of phenol on bifunctional Ni-based catalysts: Effects of Mo promotion and support. Applied Catalysis B: Environmental 238, 147–160.
At 310 °C and 3 MPa H2, Mo promotion increased reported phenol conversion by 18% on alumina and 38% on amorphous silica–alumina; the maximum conversion reported was 96% over Mo–Ni/ASA. Cyclohexane and cyclohexanol were principal products. This supports promotion under those specific conditions, not a universal NiMo ranking.
DOI: 10.1016/j.apcatb.2018.07.012 · Evidence: publisher-linked postprint/indexed record; full methods not independently audited for this summary.
Phan et al. (2020) — guaiacol, spray-pyrolysis NiMo/Al2O3–TiO2
Direct; reduced catalyst
Spray pyrolysis synthesis of bimetallic NiMo/Al2O3–TiO2 catalyst for hydrodeoxygenation of guaiacol: Effects of bimetallic composition and reduction temperature. Journal of Industrial and Engineering Chemistry 83, 351–358.
A 10 wt% Ni–20 wt% Mo formulation is reported at 98% conversion and 100% hydrocarbon selectivity (85% cyclohexane, 13% methylcyclohexane, 2% toluene), with 24 h stability reported. The paper explicitly investigates reduction temperature. These figures are study-specific and should not be compared directly with batch phenol studies.
DOI: 10.1016/j.jiec.2019.12.008 · Evidence: indexed/publisher record; detailed condition matching across studies not performed.
Adilina et al. (2019) — guaiacol on pillared clay
Direct; reduced and sulfided states compared
Hydrodeoxygenation of Guaiacol as a Bio-Oil Model Compound over Pillared Clay-Supported Nickel–Molybdenum Catalysts. The Journal of Physical Chemistry C 123, 21429–21439.
The H2-reduced NiMo-PILC was prepared at 773 K for 3 h and showed moderate activity at 623 K/20 bar, with a broad product distribution and some unidentified products. The same-study sulfided catalyst's complete conversion/77% phenol result is not evidence for the reduced catalyst and is intentionally not used to characterize reduced NiMo.
DOI: 10.1021/acs.jpcc.9b01890 · Evidence: abstract/indexed record; reduced-state outcome is qualitative in accessible summary.
Hydrodeoxygenation of Phenol Over Hydrotreatment Catalysts in their Reduced and Sulfided States (2014)
Direct state comparison; outcome detail limited
The Open Catalysis Journal 7, 18–31 (2014). Compares reduced and sulfided CoMo, NiMo and NiW catalysts on γ-Al2O3 and TiO2 for phenol HDO. This establishes a directly relevant catalyst-state comparison, but the accessible record did not provide enough NiMo-specific quantitative results for a ranking.
NiMo count caveat: Four relevant reduced/reduced-versus-sulfided papers were screened, not seven. Several apparently attractive papers were excluded from the strict set: Ni–Mo nitride/carbide catalysts (different active phase) and MOF-derived NiMo carbon where a separate H2-reduction activation step was not confirmed in the accessible evidence. Sulfided performance was not counted as non-sulfided performance.
Ni–VOx: direct evidence and limits
Zhou et al. (2025) — Ni–VOx/SiO2 interface, m-cresol
Direct; non-sulfided reduced Ni–VOx
Efficient catalytic hydrodeoxygenation of lignin derived phenolics on Ni-VOx interface. CIESC Journal 76(12) (2025), 6366–6375.
The publisher abstract reports that Ni alone favors hydrogenation and C–C cleavage and gives low toluene selectivity; an appropriate VOx amount reduces Ni particle size, increases Ni–VOx interface density, and improves selective m-cresol conversion to toluene. Methylcyclohexanol probing is interpreted as supporting direct deoxygenation as the main route. H2-TPR and reduced catalyst characterization are reported.
DOI: 10.11949/0438-1157.20250519 · Publisher record · Evidence level: publisher abstract/metadata; full-text numeric conversion, selectivity, rate, composition and reduction protocol were not independently audited.
Vanadium conclusion: Yes—vanadium is scientifically plausible as a promoter/interface component worth testing. The direct precedent suggests a pathway-selective effect (m-cresol → toluene), not necessarily superior total HDO rate or broad guaiacol/lignin-oil performance. One direct paper cannot establish reproducibility or an activity ranking. The search also surfaced a V-containing H4PMo11VO40 + Ni/C guaiacol study, but V is embedded in a Mo heteropolyacid and the stipulated reduced Ni–V/VOx state is not established in the accessible abstract; it is adjacent evidence only, not counted.
Mechanistic context—not qualifying Ni–V papers
Ni–MoOx/SiO2 (Zhao et al., 2019): reduced Ni–MoOx interface promoted m-cresol-to-toluene selectivity; useful oxide-interface analogue, but Mo is not V. DOI 10.1021/acscatal.9b01285.
Ni–Re, Ni–Fe, Ni–Co examples: show that bimetal/promoter effects and product pathways are support- and condition-dependent; they are not evidence for V itself and are not included in the NiVOx count.
NixMoyN/C (2024): high guaiacol HDO performance is reported for Ni/Ni2Mo3N/β-Mo2C phases. This is nitride/carbide active-phase evidence, not conventional H2-reduced NiMo, and excluded. DOI 10.1039/D4GC02298J.
Practical interpretation
For demonstrated breadth, NiMo currently has the larger direct evidence base in the screened set, including phenol and guaiacol and multiple supports. Do not turn the reported conversions/selectivities into a head-to-head score.
For a V hypothesis, test selective oxygen removal rather than conversion alone. Include m-cresol (direct precedent) and guaiacol (broader functionality), quantify toluene/cycloalkanes/oxygenates, and report carbon balance and time-on-stream.
Use matched controls: Ni/support, V/support, physical mixture, and Ni–VOx/support across a controlled Ni:V series. Match Ni loading, support batch, reduction ramp/temperature/time, passivation, particle size as far as feasible, H2 pressure, temperature, solvent and residence time.
Characterize the working-state interface: H2-TPR, chemisorption, XPS/XAS where available, TEM/STEM-EDS, and post-reaction oxidation/state checks. Nominal composition alone does not prove Ni–VOx interfacial sites.
Report comparable metrics: conversion; carbon-based selectivity and yield; oxygen removal/deoxygenation; rate normalized to catalyst mass and exposed Ni (if measured); deactivation and carbon balance. Separate H2 feed pressure and solvent-mediated hydrogen transfer.
This is a screening recommendation, not a published optimum or proof that V will outperform Mo.
Evidence and limitations
Bibliography is relevance-selected, not a citation-count ranking.
Strict requested threshold: at least seven qualifying papers per family. Verified here: four NiMo reduced-state studies (with varying accessible outcome detail) and one direct Ni–VOx study. The threshold is unmet for both.
Some performance details are abstract/index-record level; the full methods, supporting information, and complete numerical tables were not audited for every article. The NiVOx paper particularly needs full-text verification of reduction protocol and quantitative results before experimental design or publication claims.
Model-compound results do not establish performance on real lignin oil. Cross-paper values are not directly comparable because reaction conditions and definitions vary.