The dataset shows a peak of 92 filings in 2018 followed by a steady decline toward 11 by 2026, with the 2022 midpoint at 69 already below the peak. This pattern is typical of a claim space where the foundational composition-of-matter and preparation-method patents were filed early, leaving later entrants to compete for narrower improvement claims. It does not mean the underlying chemistry has stopped being used commercially — production and licensing activity can continue for years after patent filing slows. Readers should also account for the roughly 18-month publication lag, which understates the true filing count in the most recent one to two years.

The assignee ranking in this dataset is led by established industrial chemical companies including Dow Global Technologies, BASF, Rohm and Haas, and research institutes such as the Dalian Institute of Chemical Physics, alongside refiners like ExxonMobil. Several of these show zero filings in the most recent tracked year, which is worth checking against publication lag before assuming a competitive shift. The strongest joint-filing relationship in the corpus is between Dow Global Technologies and Rohm and Haas, with 75 co-filed families — far ahead of the next pairing.

1,003 of the 1,562 records in this corpus also carry a C07C classification, covering acyclic and carbocyclic organic compounds. That overlap means most heterogeneous catalyst claims are filed in the context of a specific reaction — commonly hydrogenation or related organic transformations — rather than as a standalone catalyst architecture claim. For a company evaluating freedom to operate, this means catalyst novelty often has to be assessed jointly with the target reaction chemistry, not in isolation.

US10143997B2, assigned to SCG Chemicals and granted in December 2018, claims a rhenium-based heterogeneous catalyst stabilized by contacting it with a stabilizing agent — an aliphatic hydrocarbon compound — at a temperature between 0 and 100 degrees Celsius. It is a process-and-composition claim over the stabilization step, not over rhenium catalysts generally. Work using rhenium catalysts with a different stabilization chemistry, temperature range, or no stabilization step at all would not fall inside this claim as described in the abstract.

The comparatively thinner IPC classes in this corpus point to the open branches: C01B (inorganic compounds and non-metallic elements) and C10G (hydrocarbon refining) each carry only 126 records against the corpus's 1,562 total, versus over 1,000 for C07C. Regeneration-cycle claims and support-metal interfacial bonding chemistry also appear underrepresented relative to composition and preparation claims. A first claim in these areas would likely target a specific regeneration protocol or interfacial structure tied to a named support material, rather than a broad catalyst composition claim, since the broad composition space is already dense with prior art.