ZnO hydrotreating update — evidence audit

Outcome

The requested minimum of 40 genuine qualifying studies is not met. Four new direct HDS/HDN/HDO papers are listed. Together with 7 inherited provisional direct-reaction records, this gives 11 provisional records—not 11 independently validated studies. The inherited inventory has 37 entries; 37+4=41, which does not meet the 40-qualifying-study threshold. The earlier report itself separates its small direct-reaction subset from RADS/adjacent records. No padding.

“Direct” means an article record explicitly reports a ZnO-containing catalyst tested in HDO, HDS or HDN. Full-text access levels are stated below. The 37 inherited records were not all independently re-audited here.

Four new direct records

Direct HDS · publisher article record/abstract inspected

Hidrodesulfuración de un diésel modelo utilizando catalizadores de CoMo soportados sobre γ-Al₂O₃–ZnO

Grey Cecilia Castellar Ortega, Luis Rodríguez Núñez & Esneyder Puello-Polo. DOI 10.15665/rp.v21i1.3101. CoMo/γ-Al₂O₃–ZnO versus CoMo/Al₂O₃ for BT, DBT and 4,6-DMDBT in model diesel. Abstract reports an enhanced DDS pathway; this does not establish enhanced total activity. Sulfided HDS, not HDO; association does not isolate ZnO’s causal role.

Publisher record

Direct HDN · full article HTML inspected

Síntesis y caracterización de NiMo₅W/Al₂O₃ modificado con ZnO para la hidrodesnitrogenación de indol

Esneyder Puello Polo, Yeiny Muñoz Montes & Miguel Caro Candezano. DOI 10.17081/invinno.10.2.6089. After 7 h the paper reports indole conversion / HDN of 95% / 67% for NiMo₅W/γ-Al₂O₃–ZnO versus 85% / 55% for NiMo₅W/γ-Al₂O₃. This is NiMoW, not binary NiMo. Two supplied AmeliCA paths point to one work.

AmeliCA full HTML · article record

Direct HDO · Crossref DOI metadata and publisher record inspected; abstract-level

Pyrolysis of Palm Fronds Waste into Bio-Oil and Upgrading Process Via Esterification-Hydrodeoxygenation Using Cu–Zn Metal Oxide Catalyst Loaded on Mordenite Zeolite

Ahmad Nasir Pulungan, Ronn Goei, Fauziyah Harahap, Lisnawaty Simatupang, Cicik Suriani, Saharman Gea, Muhammad Irvan Hasibuan, Junifa Layla Sihombing & Alfred Iing Yoong Tok. Waste and Biomass Valorization (online 13 May 2023; print 2024). DOI 10.1007/s12649-023-02153-0. Two-stage palm-frond bio-oil esterification/HDO uses CuO/ZnO/mordenite and single-oxide controls. Direct HDO candidate, but combined catalyst/staging prevents attribution to ZnO alone; full-text outcome audit remains.

Direct HDS · bibliographic record / abstract-level

Hydrodesulfurization of dibenzothiophene over ZnO-modified NiMoW catalysts in continuous flow

Tomina et al. DOI 10.1134/S0965544115070129. ZnO-modified NiMoW catalyst for DBT HDS in continuous flow. Direct HDS candidate; do not interpret this as HDO or as independent validation beyond the available bibliographic evidence.

Adjacent, phase-unconfirmed, or duplicate leads

Zn/SiO₂ phenol HDO (two publications; linked study line)

10.1016/j.biombioe.2020.105556 is an adjacent phase-unconfirmed lead. DOI 10.3390/en13112802 is inherited from the prior report and is a duplicate, not a new work. Operative Zn phase is unconfirmed; neither is counted as a new ZnO-confirmed study.

Zn-promoter HDS/HDN: three phase-unconfirmed DOI leads

10.1002/bscb.19870961107 · 10.1016/0016-2361(95)92667-U · 10.1021/ie00059a001. A Zn-promoter label alone does not prove ZnO is the reaction-phase species; not counted as ZnO-confirmed.

Cu–ZnO–Al₂O₃ guaiacol HDO: inherited duplicate

Crossref verifies 10.1016/j.ces.2023.119616, “A Cu-ZnO-Al₂O₃ catalyst with oxygen vacancy for efficient hydrodeoxygenation of lignin-derived guaiacol to hydrocarbons” (Liu et al., Chemical Engineering Science, 2024). Already listed as prior item 1; not new.

ScienceDirect PII unresolved

PII S0009250923011727 yielded no verified title/catalyst metadata. Excluded from counts. No duplicate relationship to the AmeliCA indole study is established.

Deduplicated ledger

Bucket	Count	Meaning
Prior report	37 claimed	Not recomputed card-by-card.
New direct works	4	CoMo HDS; NiMo₅W indole HDN; Tomina et al. NiMoW/DBT HDS; Cu–Zn oxide/mordenite staged HDO.
Inherited plus new inventory	41 entries	37 inherited + 4 new; still not 40 independently validated qualifying studies.
Provisional direct-reaction records	11	7 inherited provisional + 4 new; not independently validated as a group.
Minimum shortfall	At least 29	Against 40, based on the 11 provisional direct-reaction records.
Prior direct count	5 reported	Earlier page’s direct HDO/author-described adsorptive HDS, not independently audited here.
Phase-unconfirmed DOI leads	5	Two Zn/SiO₂ + three Zn-promoter HDS/HDN; excluded from confirmed ZnO count.
Additional candidate	1 duplicate	CES guaiacol paper already inherited.
Verified qualifying 40-paper corpus	Not achieved	Explicit shortfall.

Verification and limitations

Search/audit date: 2 November 2026. publisher page inspection for CoMo HDS; full HTML inspection for indole HDN; Crossref metadata for the palm-frond DOI, both Zn/SiO₂ DOIs and CES guaiacol DOI. AmeliCA paths are one article. The ScienceDirect identifier S0009250923011727 remained unresolved.

Limits: prior 37-entry corpus was not fully re-audited; complete text/SI review of all additional studies and exhaustive search to 40 were not completed. This update does not claim 40 qualifying papers or comprehensive coverage.

Prior report →